Aircraft Materials PDF

M6 – MATERIALS AND HARDWARE PROPERTIES OF MATERIAL AIRCRAFT MATERIALS- GENERAL 15) Enables a material to resist penetration, wear, or cutting action...

M6 – MATERIALS AND HARDWARE PROPERTIES OF MATERIAL AIRCRAFT MATERIALS- GENERAL 15) Enables a material to resist penetration, wear, or cutting action a) Hardness AIRCRAFT MATERIALS 16) Ability of a material to withstand forces which tend to deform or the ability of a material to resist stress without breaking METALLIC NON METALLIC a) Strength -Materials having the nature of metal or containing metals -Materials containing no metal 17) Ability of a material to be stretched and go back to its original state or recover FERROUS NON FERROUS -Iron or alloy containing -Metal which contain no PLASTICS CERAMICS NATURAL a) Elasticity iron iron 18) The property of metal which allows it to be reshaped. a) Plasticity PURE ALLOY PURE ALLOY PVC PORCELAIN RUBBER 19) The ability of a metal to be drawn into thinner sections without breaking and can resist deformation in tension DEFINITIONS a) Ductility 1) A load that is uniformly distributed over a certain area and also the 20) The ability of a material that allows it to be stretched o shaped by per unit of area expressed is PSI beating with a hammer or passing through rollers and can resist a) Unit stress or stress deformation through compression 2) A kind of stress that results in the tending to stretch or lengthen the a) Malleability material 21) The property of a material that allows it to be deformed without a) Tensile Stress 3) A force that compresses or shortens the material breaking a) Compressive stress a) Toughness 4) NOTE: TENSILE AND COMPRESSIVE STRESSES ALWAYS ACT AT RIGHT 22) Ability of a metal to break when deformed or hammered. It is the ANGLES NORMAL TO AREA BEING CONSIDERED. resistance to change in the relative position of molecules within the 5) A force that results two metal riveted to each other which causes material sliding motion or shear a) Brittleness a) Shearing stress 23) Ability of a material that makes it possible for it to transmit heat or 6) A force that twists the material. electrical conduction a) Torsion Stress a) Conductivity 24) Ability of a material that enables it to withstand force over a period of time a) Durability METAL GENERAL 25) Number of metals used in applications in technical fields a) 70 metals (chemical elements) 26) Density of airframe constructions light weight metals in kg/dm3 a) 7.85 kg/dm3 (3x the density of Al) and 53) Any wetting with acidic fluids or Mordants can lead to susceptibility to corrosion a) Hydrogen Embrittlement b) can increase corrosion resistance by adding alloying agents 40) Application of stainless steel in an aircraft STEEL ALLOYS AND HEAT TREATMENT a) Between 8 and 16 % (Airbus 320: 9%, Boeing 777: 11%) - To change property, add hardness and strength 41) Primary advantages of high-strength steels - Heating to high temp a) High strength and high modulus of elasticity - Has to contain at least 2% carbon to be hardenable 42) Steel composition - High temp = fragile=hard= grains not concentrated - Low temp= grains are tight a) Iron and Carbon - Orange right temp 43) Iron is extracted from - Less carbon needs more temp a) Iron ore > Pig iron (raw material of steel) - More carbon needs less temp STEEL GRADES 54) Hardening process STEEL GRADES annealed above GSE line -Different kind of steels and are distinguished by the Put in a furnace fo a specific time then quench specific properties Annealing Non- Alloyed Alloy Steel Steel rapid cooling of material afetr heating (soft anneal) quenched in water or oil. to retain the strength properties gained Construction Low Alloy Steel Carbon steels High Alloy Steel,>5% become untempered martensite(hard and brittle) steels ,12% Stress tempering chromium Relieving steels Anneal CRES (Corrosion HHT (High Resistant Steel) strength steel- 55) Heat treated steels may NEVER be welded or heat Heat Treated) – non cutting a) straightened or their structure will RESHAPE shaping process // cold short 56) Applicable for steel components, which are hardened and have to be softened for mechanical processing, also called the zero state a) Soft Annealing (becomes austenite: soft and ductile) – after NOTE: non alloy steel, CARBON CONTENT IS FOR HARDENING heat treatment 44) Letter used for “Structural Steel” according to EN 10027 standard 57) Serve for structure refinement and releasing internal stresses in the a) S component. Reduces stress and strain before machining 45) Letter used for “Mechanical Engineering Steels” or german word a) Normalizing and Stress Relief Annealing “Einsatzstahl” (case hardening steel) 58) High alloy steel, >5%. a) E a) Demands resistance to high temp corrosion 46) HHT steel that is the common steel alloy for use in the 180-200 ksi 59) Cres 14-4-ph range a) _% chromium-_% nickel – precipitation hardening a) 4130 60) PH- precipitation hardening 47) HHT steel that has a strength range of 200 ksi up to 280 ksi and a) Increases the yield strength by temperature depending solution commonly used in 260-280 ksi range of aluminum atoms within the iron-crystal a) 4340 61) Stainless steels are treated on when in contact with lightweight 48) HHT steel that is commonly used is landing gear components and has alloys and the protection is for the other material not the stainless 240-290 ksi range steel. a) 300M a) Surface protection- sacrificial metal layer MATERIAL DESIGNATION OF HHT-STEELS i) Stainless steel- to avoid galvanic corrosion AISI- STANDARD – 1ST digit primary alloying element/ 2nd digit % of prime ii) Non-stainless steel- painting, AL spraying element/ 3rd and 4th content of carbon in 1/100% 1 = carbon or manganese M6.2 AIRCRAFT MATERIALS – NON FERROUS 62) Used in aerospace industry because of light weight, high strength, 2= Nickel heat resistant, corrosion resistant and has approximately 56% of the 3= Nickel Chromium density of steal 4= Molybdenum Alloy Steel a) Titanium 5= Chromium 6= Chromium-Vanadium i) Density 4.5 kg/dm3 450degC 7= Tungsten- Chromium ii) Poor heat conductor 8= Nickel-Chromium-Molybdenum (1) Advantages: low weight, high strength (+alloying 9= Silicon-manganese or Ni-Cr-Mo agent), high corrosion resistant, low thermal NOTE: American Institute of Steel and Iron / SAE Soc of Automotive engr. conductivity, good heat resistance (sensitive to 49) A process that increases the yield strength by temperature hydrogen embrittlement) depending solution of aluminum atoms within the iron-crystal (2) Not castable. Can only be welded by inert gas or a) Precipitation Hardening (PH) vacuum (3) In A/c construction STR rivets air ducts /ENG fan area PROPERTIES OF HHT 63) Tensile strength of pure aluminum is 50) Small surface damage such as scratches, nicks, or corrosion, localized a) Between 300 and 700 N/m2 stress concentration 64) Most important titanium alloy in aircraft construction a) Notch Sensitivity a) Ti6Al4V 51) Occurs when low- alloyed steel are deformed chip less in the cold 65) Most common alloying element of Titanium state. a) Aluminum a) Cold Shortness Sensitivity  76) Aluminum alloy that undergoes natural aging a) 2024( solidifies in 3-8 days, after 8 hrs, 90% of strength is 66) When Titanium is exposed to temperature above 450o it must be achieved) protected from the atmosphere. Contact with media which releases hydrogen is dangerous for titanium, especially when heated above Basic Temper Designation 150oC because this leads to F- Fabricated a) Hydrogen Embrittlement. O- Annealed 67) Heat resistance of titanium alloy when used in compressor blades H- Strain Hardened (non heat treatable prods.) a) 520oC W- Solution Annealed (instable Intermediate State) 68) This metal is three times lighter than steel and has a melting point of T- Heat treated to produce stable tempers 660oC 77) Aluminum alloy that undergoes artificial aging and the temp is about a) Aluminum 2.7 kg/dm3 660degC 120-200oC b) one pound has more than twice the electrical conductivity of a) 7076(solidifies in 6-7 hrs) copper 78) Quenching interval c) pure form high resistance but soft, if hardend resistance a) 5-15 seconds decreases i) Water bath 20 to 38 deg C Cast Aluminum Alloys Wrought aluminum alloys 79) State of material after quenching a) W-State 80) Carried out in aluminum alloys to bring the material into the good flowability in the liquid state can be formed non-cutting in the cold minimum state of hardness and strength, whilst achieving the state, which means the can be drawn, clenched, milled and forged maximum stretch a) Soft Annealing(zero state and done between 400-454oC) castable b) After soft annealing aluminum MAY NOT BE QUENCHED 81) AlCuMg-alloy in a soft annealed temper which is the 0-state when forged grain hardens very coarse grain str a) 2024-0 82) AlCuMg-alloy in a hardened temper, and is solution annealed, brittle quenched, strain hardened and naturally aged a) 2024-T3 83) AlZnCuMg-alloy in a hardened temper, and is solution annealed, used @ wheel rims quenched, and artificially aged 69) Good resistance against external damage a) 7075-T6 a) Non-hardenable AL Alloy 84) A layered composite material that is a member of a family of 70) The strength depends on the alloy content and can be increased by_. materials called FML. An is an optimized FML for aircraft and consist a) Strain Hardening of alternating layers of aluminum and glass fibre prepreg layers a) GLass Aluminum REinforced Laminate 71) Can be heat treated to increase strength i) Used on fuselage skin structures on A380, aircraft cargo a) Hardenable AL Alloy 72) A process that means to permanently weld metals layers onto a basis bay floors and liners, aircraft cargo explosive resistant material, whilst applying high pressure. For corrosion protection containers 85) Materials that consist of thin layers of metal sheet and unidirectional a) Cladding i) Clad thin layer of pure aluminum Polyaddition `Polymerization Polycondensation A chemical reaction, A chemical reaction ii) ALCLAD / CLAD generally carried out between two similar Reaction of two 73) Thickness of clad layers in a presence of a or dissimilar basis different types of a) 3-5%(sheets with thickness that exceeds 6mm are not catalyst, which units which have at molecules when cladded) combines small least two functional reactive groups are 74) STANDARDIZATION OF ALUMINUM MATERIALS molecules(monomers) groups brought together , containing a double with by- Alloy number Major Elements w/out by product bond into a long chain product:water,hyd 1XXX ALUMINUM molecules Most famous acid products of 2XXX COPPER Monomer molecules Most famous polyaddition 3XXX MANGANESE may be: product of Polyurethane and 4XXX SILICON Ethylene polycondensation Epoxies 5XXX MAGNESIUM polymerizing to a)Phenol – 6XXX MAGNESIUM AND SILICON Polyethylene (PE) formaldehyde Styrene (Bakelite)- resin 7XXX ZINC polymerizing to thermoset 8XXX OTHER Polystyrene (PS) 9XXX UNUSED Vinyl - chloride 75) HARDENING OF ALUMINUM ALLOYS polymerizing to Solution annealing Polyvinyl- chloride (PVC) The material is heated or a specified temp in a specified time in furnace or salt bath fibre layers embedded in an adhesive system furnace a) Fibre Metal Laminate(FML) Quenching The material is carried out in a water bath with 20o to 38o. after this the material is soft and ductile Natural and Artificial Aging Hardening of a material in room temperature or in a furnace T3- Natural Aging (Manufacturer) T4- Natural Aging (installer or MRO) T6- Artificial Aging M6.3 COMPOSITE and NON METALLIC Honeycomb Fabrication PLASTIC PRODUCTION 96) A process which the bonding of honeycomb is done one at a time 86) Thermoset is irreversible a) Corrugation process 87) Thermoplastic is reversible by application of heat 97) A process which the bonding of honeycomb is done with all materials bonded simultaneously COMPOSITE GENERAL a) Expansion process 88) Term used to describe two or more materials that are combined to 98) Layers that build up a monolithic wall form a much stronger structure than either material itself and is used a) 5 layers mainly to reduce weight 99) Layers that build up a honeycomb or sandwich a) Composite a) 7 layers i) ADVANTAGES 100) A type of construction where a core material is the center member of (1) To reduce weight the assembly (2) High strength to weight ratio a) Sandwich construction (3) Reduction of parts and fastener Other core mat: Styrofoam, urethane, wood (4) Reduction of wear SEALANT AND BONDING AGENTS (5) Corrosion resistance Adhesive ii) DISADVANTAGES 101) Used to bond two or more surfaces together. Used to distribute (1) Expensive stresses at bonding points and are moisture and corrosion resistant (2) Not easy to repair and eliminates the need for bolts and rivets (3) Hazardous a) Adhesives i) HOW TO KNOW IF ADHESIVE IS EFFECTIVE? REINFORCING MATERIAL (1) Resistant to slippage, malleability, cohesive strength, FIBERGLASS ARAMID GRAPHIT adhesion 102) Known as polymerization adhesives and used as a modifier of natural 1)Made from small 1)Characterized by its 1)Has good mechanical strands of molten yellow color, properties and is very adhesives to perform better have a greater range of application silica glass and then lightweight and its strong and stiff, a) Synthetic adhesives spun together and excellent tensile which is mainly used 103) Synthetic adhesive or natural adhesives based on Silicon woven into cloth but strength for its rigid properties weighs more and has good for high stress and good a) Elastomeric Adhesives less strength than and vibration compressive strength 104) Transformed into tough, heat resistant solids by the addition of other reinforcing A.K.A KEVLAR but more brittle than catalyst or by application of heat e.g. epoxy resins material KEVLAR LOW COST MOST a)Black Graphite/ a) Thermosetting adhesives POPULAR Carbon Fiber 105) Atmospheric pressure is used to press two solids together so there Hybrid fiberglass b)Corrosive when will be no air between the two plane parallel surface a)Quartz – fiber bonded to a) Contact adhesives -Fibreglass is mainly aluminum used in Nose 106) Contains plastic and resins dissolved in a solvent Radome a) Solvent adhesives 107) Adhesives dissolved in water solution GFRP- Glass Fiber Reinforce Plastic a) Dispersion adhesives CFRP- Carbon Fiber Reinforce Plastic 108) Bonding of Same Material AFRP- Aramid Fiber Reinforce Plastic a) Cohesive QFRP- Quartz Fiber Reinforce Plastic STYLES OF FABRIC 109) Bonding of different material a) Adhesive ROVING MATS FABRICS Resins 1)Style of fabric which 1)Area measured 1)They are area 110) Bonding substance of composite and most likely be liquid in form denominates fibres materials which are measured materials a) Matrix which are combined not oven and made which cross to fibre bundles in out of or cut or non- rectangularly with Thermosetting- hardening is irreversible. Used in A/c str large amount without cut, multidirectional warp threads and 111) Resins that are best used in aircraft external structures. Used in high- any twist and nearly laying fibres which filling threads tech composites because their mechanical properties are superior to parallel. are fixed by sprayed 2)A reinforcing 2)When many rovings on binder material in composite those of polyesters are laying side by side and most likely be in a) Epoxy resins in a mat, it is called solid form i) DISAVANTAGES a)Unidirectional tape (1) TOXICITY (can cause dermatitis) 89) Longest thread with marking (2) LOW POT AND SHELF LIFE a) Warp (3) COST PREPREGS 112) Resin + hardener ratio 90) Fibers that are already impregnated with resin in the production a) By volume process and then cooled down very fast which start to cure when 113) Adhesives that are best used inside the aircraft structures/cabin. Low heat is applied. toxicity a) Prepreg/ Pre-impregnated Fibres a) Phenolic Resins 91) Used to connect GFRP (resin – resin connection Thermoplastic resin- hardening is reversible. Not used in A/c str a) Standard – Prepreg 114) Does not have the quality for structural components because it does 92) Used to connect GFRP laminates with honeycombs or sheet not bond well to fibres metal parts a) Polyester resin a) Bonding – Prepregs 115) The most important factor for bonding, and is frequently expressed 93) Percentage of resin in and “Elitrex” with the contact angle that is formed between a droplet of a liquid Prepreg Resin Content and a solid i) Standard 38% a) Surface wetting ii) Bonding 50% 116) Take into account that the adhesives must penetrate into the cavities 94) During the curing process in an autoclave or in a heating press, 18- before curing to prevent bubbles 20% of resin is pressed out a) Mechanical Hooking a) Resinflux 117) The amount of time you have to work with the resins CORE MATERIAL a) Pot Life 95) The third component of a composite structure 118) The time which the product is still good in an unopen container a) Core Material a) Shelf Life i) Foam- filler material 119) Too much resin is used and affects the strength of the composite by making the part brittle and add extra weight ii) Honeycomb- excellent strength to weight ratio a) Resin rich DETECTION OF DEFECTS/DETERIORATION IN COMPOSITE AND NON- 22) Consist of two half cells and a noble metal and a base metal, which METALLIC MATERIAL serves as electrodes and are each in a sulfate solution Damage to composite structures- specified in SRM + NTM a) Galvanic cell 1) Damage classification 23) forming of oxide films/exposed from oxygen causes corrosion a) Allowable a) Oxidation b) Repairable 24) Absorbing of electrons c) Non repairable a) Reduction 2) Denomination of a process to abrade the bonding surfaces with a 25) Oxidation Is Loss, Reduction Is Gain chemical treatment in order to enlarge the adhesive surface 26) presence of aggressive chemical in the atmosphere/ without a) Pickling ELECTROLYTE 3) A result with a contact with a sharp object and only the surface of are a) Chemical corrosion affected and the edges are sharp 27) Electrically conductive fluid or moisture a) Scratch a) Electrolyte 4) Wider and deeper than a scratch, several plies are affected. But edges 28) A galvanic dissolution that commonly occurs between adjacent are generally smooth components, whose metals have different electrochemical potential a) Gouge and under the influence of electrolyte 5) Gouge and scratch repaired by a) Electrochemical Corrosion a) Removing the damage plies and hand lay- up 29) Also called the Microbes corrosion and is caused y a direct chemical 6) Damage to a surface caused by scuffing, rubbing, or scraping of the attack of metabolic products of microorganisms component a) Biological corrosion a) Abrasion 30) When mechanical forces act on a component which leads to 7) When humidity penetrates a sandwich structure this happens corrosion a) Corrosion on sandwich structures a) Stress corrosion 8) Separation of materials or laminates due to adhesive failure 31) Corrosion color in steel a) Debonding a) Red rust (hydrated ferric oxides) 9) Separation of plies and mostly because of resin failure 32) Corrosion product on aluminum a) Delamination a) White – grey powdery material 10) Method used to detect water absorption 33) Special form of crevice corrosion which occurs on metals surface a) NDT/ Thermograph having an organic coating system and is identified by wormlike trace 11) A deformity caused by extraneous forces, which are applied to the of corrosion structure a) Filiform Corrosion a) Depression or Dent 34) Corrosion that is a combination of stress and corrosion 12) Repair recommended for small damage on honeycomb materials and a) Stress corrosion loses half of the material’s original strength 35) Used as protection on titanium a) Filling repair a) Chromium acid anodize 13) Consist of applying several layers of fabric material impregnated with 36) Used as lubricant for fastener a resin onto the repair surface, in order to restore the damaged skin. a) Cetylalkohol a) Wet Lay – Up i) Most cathodic is Carbon TYPES OF CORROSION 14) To use atmospheric pressure to consolidate layers in the laminated ii) Most anodic is Magnesium LAHAT repair. it is used to consolidate the layers in the laminated repair, 37) Occurs when two dissimilar metals make electrical contact in the remove trapped air and gases produced during curing, hold heater presence of an electrolyte blankets, thermocouples and other materials in place during the a) Galvanic Corrosion curing cycle and produce desired surface finish on the repair 38) The most common type of corrosion on aluminum and magnesium a) Vacuum Bagging and appears a white powdery deposit and the starting point for M6.4 CORROSION intergranular corrosion 15) Defines as an undesirable, natural reaction of materials with a) Pitting Corrosion extend vertically into material substances in their environments 39) A corrosion on the grain boundaries of the metal and occurs when a) Corrosion (derived from Latin word corrodere which means cladding is damaged “gnawing away”) a) Intergranular Corrosion i) Influence Factors of Corrosion 40) Mostly seen on extruded sections, this advanced type of intergranular (1) Type of metal corrosion exhibits itself by lifting up the surface of a metal by force (2) Anode and cathode a) Exfoliation Corrosion (3) Temperature 41) Results in the rubbing movement between two heavily loaded (4) Presence of electrolyte surfaces and can eventually cause cracking fatigue (5) Heat treatment a) Fretting Corrosion 16) Occurs due to the tendency of most metals to return to their natural 42) A corrosion cause by bacteria, fungi or yeast in an unclean fuel and state by combining it with atmospheric oxygen looks like a sludge like deposit. a) Corrosion of metals a) Microbial Corrosion 17) Noble Metals such as gold and platinum do not corrode since they 43) Necessary if a contamination of fuel tank is detected are chemically pure. a) Biocide (kathon or biobor) 18) Corrosion on the surface grains of the metal because of its crystalline 44) Occurs between two materials that come into contact, metallic or structure and happens at the boundaries between grains non-metallic a) Intercristalline corrosion a) Crevice Corrosion 19) Material used as coating of a metal and used as anti-corrosion i) Solid rivets are Self-sealing fasteners a) pure aluminum coating (AlClad) ii) For shearing loads in fasteners small head is used for 20) Preventive measures on corrosion weight saving i) Steel requires cadmium plating, zinc plating and aluminum coating, etc. ii) Aluminum alloys are usually anodized iii) Magnesium and magnesium alloys requires special chemical and electrochemical treatments and paint finishes. 21) The corrosion process that takes place at the surface of the electrode under the influence of electrolyte and creates a half cell a) Electrochemical Reaction M6.5 FASTENERS 45) Fahrenheit to Celsius a) 46) Celsius to Fahrenheit a) 47) Used to attach components or assemblies to the aircraft structures a) Fastener 48) used to attach high-strength components to the assemblies a) aluminum solid rivets 49) used for joints in high-temp areas a) steel, titanium or monel fasteners Fastener Thread standards SPECIAL FASTENERS 54) thread with an angle of 55 degrees RIVETS - have close- tolerance BLIND FASTENERS a) British Standard Whitworth (BSW) shank or pin 55) Finer version of the whitworth thread form and the smaller thread -Fastener for hsear app provides a finer form of adjustment and greater resistance to Fastener for tension vibration in all fastening devices app Pull-through a) British Standard Fine (BSF) Solid Blind Rivets 56) This is another fine-pitch adaptation of the whitworth thread form. It deforms its back when a tension load is applied is used for pipeline couplings where the fine pitch ensures that Threaded pin in front sufficient uncut metal remains on the wall of a pipe to guarantee a Hi- lok-normal OP strong connection Hi-lite- for weight a) British Standard Pipe (BSP) Huck, Avdel 57) Has a thread angle of 47.5 degrees saving Bull nose a) British Association (BA) Swaged pin 58) They have a thread angle of 60 degrees lockbolt a) ANC and ANF (American National Coarse and Fine) Cherry max, 59) Incorporates features from both American and British ntnl threads Chobert a) Unified 60) A screw that has a deeper thread and have fewer threads, greater lead Taper-lok a) Coarse Pitch Blind Bolts 61) A screw that have a stronger root portion, tighter grip and more resistant to shaking loose, strong against vibration, a) Fine Pitch 62) Most common thread form and shaped to combine strength with Bolts ease of engagement a) Vee Thread M6.5.1 SCREW THREADS i) Install bolts and screws foremost and uppermost 50) If groove is formed on the external M6.5.2 BOLTS, STUDS AND SCREWS a) Male thread 63) Install nuts not less than what of the bolt 51) If groove is formed internal a) 1/32 in (0.8mm) a) Female Thread 64) Torque values are at what manual 52) Thread formed on a cylinder is known as a) SRM ch51 or AMM a) Straight or Parallel Thread 53) Thread formed and cut onto a conical part a) Taper thread Features Shape of one complete contour of FORM the thread between corresponding points on the thread Prominent point of the thread, it is CREST the top of the thread ROOT Bottom point of the thread groove Slope of the thread between the FLANK root and crest THREAD ANGLE angle between two adjacent flanks male: diameter of the crest MJR DIAMETER female: diameter of the root male: root diameter MNR DIAMETER female: crest diameter 65) It is where the code marking of aircraft bolts are identified a) Bolt head radial distance between root and DEPTH i) NE = Long Thread crest ii) NF= Short Thread distance between corresponding iii) Diameter of bolt is always in 1/16 PITCH points on adjacent thread forms iv) Diameter of Hi- Lok and Rivet is always 1/32 v) Grip Length is always 1/16 distance that the moving member of 66) T> 2.4mm = max 2 thread pitches LEAD the mating pair advances axially 67) T< 2.4mm = no thread pitches w/in the hole 68) Maximum of 3 washers may be used to adjust a grip length a) (1 under the head, 2 under the nut) 69) A piece of rod, threaded at each end with a plain portion in the 78) It consists of a receptacle , stud and cross pin. It has two types which middle is the fixed type and floating type a) Stud a) Airloc Fasteners 70) A piece of a hexagonal metal bar, drilled and tapped through its axial 79) used to secure bolts, screws, nuts and pins center – line a) Cotter Pins a) Stud box 80) Given to a specially – shaped piece of metal that is used to transmit at 71) Used extensively to secure thin – gauge sheet metal parts where nuts considerable mechanical power from a shaft to hub and bolts are either impractical or too expensive a) Keys a) Self-Tapping Screws i) A. Taper Keys Nuts (4) Hollow Saddle Key- is hollowed to fit the radius of the 1.Non- Self Locking Nuts (4) shaft -Are used with drilled shank hex head bolts, clevis bolts, eye bolts and Flat saddle key- is a rectangular or square section that is rivets and is designed to lock cotter pin or wirelocking driven into a keyway in the hub and bears upon a flat on Classifications: the shaft Shear Castle Nut – used only for shear load on clevis bolts Gib headed key- is fitted into keyways which are Castle Nut- Are designed to fit on standard airframe bolts and machined partly in the shaft and partly in the hub. It is may be used when the bolt is subjected to either shear or tensile strength capable of transmitting a much greater driving load than the saddle type keys Slotted Engine Nut- designed for use on aircraft engine and is not approved for airframe use. Made of Heat- treated steel Feather key- is used when axial movement is required Wing Nut- intended for use on hose clamps and battery between the hub and the shaft connections where the desired tightness is ordinarily obtained by Woodruff key- is made in the shape of a segment of a the use of fingers parallel sided disc similar to capital D. it is suitable for fitting 2.Locking nuts (5) not reuseable to either parallel or taper shafts. Lock nut- Is a thin, plain nut which is tightened down firmly M6.5.4 RIVETS onto the main, plain nut. 81) Deformed portion of the Rivet Nyloc Stiff nuts- has an unthreaded nylon insert permanently a) Upset Head housed at the outer end i) Selection of correct Rivet diameter is at least 3 times the Oddie Stiff nuts-Have six tongues at their outer end which are thickness of the thickest sheet being joined bent inwards to form a circle slightly less in diameter than the minor diameter of the bold thread Aluminum Alloy Rivets- Used to attach aluminum alloy components Aerotight and Philidas Stiffnuts- have slotted locking where a low-strength rivet is sufficient to hold the load extensions which are closed during manufacture to put the screwthread Monel Rivets- Without heat treatment before use, are used in steel, out of alignment titanium or aluminum alloy riveted assemblies 72) is used when a slight range of movement is necessary to ensure the Titanium Rivets - Are rivets with a cylindrical or a partial tapered shank. bolt can locate No heat treatment is necessary for this type of rivet a) Anchor Nuts 3.High- temp self- locking Nuts – temp self locking >121degC (250F) 4.Low- temp self- locking Nuts - temp self locking < 121degC (250F) 73) Permit each thread to adjust to the screw and assure full load distribution throughout the entire length of the thread, Protection for soft material a) Heli – Coil Inserts M6.5.3 LOCKING DEVICES 74) A process of securing all aircraft bolts, nuts, screws, pins and other fasteners so that they do not work loose due to vibration a) Safetying 75) Most positive and satisfactory method of safetying and is a method of wiring together two or more units in such a manner that any tendency of one to loosen is counteracted by the tightening of the wire a) Wirelocking 76) Most common method of wire locking a) Double - Twist Method Washers 1. Spring Washers- either a single coil or square section spring with sharp corners or a double coil spring. 2. Tab Washers- is a metal washer with two or more tabs, suitable for use with plain nuts. One tab is bent against one of the flats of the nut and the other is bent over an edge of the component or fitted into 82) a process which a rivet material have to be heat treated before using or hole machined in the component. Not reusable them in the manufacturing process 3. Shakeproof Washer- is a spring steel washer with slanting serrations a) Solution Annealing( Annealed at 495o and quenched at 20o) on its internal or external circumferences i) At -18o temperature rivets can be stored for up to 7 days Quick release Fasteners ii) At -20o temperature rivets can be stored for up to 20 days 1. Pip pin - is a simple and secure, non-threaded fastener, allowing rapid installation and removal of parts without tooling 83) the time between opening the furnace or removing the rivets from A. Ring Pull Detent Pin- A single ball locates the pin, no positive the salt bath and the complete immersion of the load into the lock quenching medium B. Double Acting Steel Pin- it is a instantaneous self locking, a) Quench Delay vibration resistant and easy application pin 84) The time, within which the rivets must be upset, at room temp. 25o 2. Camloc Fasteners – designed so that it can be quickly inserted into the a) Maximum Handling Time grommet by compression of the spring 85) A tapered bolt with a threaded end and a self – locking nut and used 77) It has 2 types which are the light duty that is used on box covers, in areas where a high fatigue performance is required access hole covers and light weight fairing and the second type which a) Taper – Lok is the heavy duty type which is used on cowling and heavy fairings 86) A combination of a rivet and a nut, resembling a hollow rivet with a) Dzus Fasteners threads inside its shank a) Rivnut 87) Combined thickness of the material to be joined 2. Journal or Roller bearings- it is the bearing that is used for a) Grip Length supporting journals, which are designed to accept forces at 88) Run along the length of a hose which are yellow, red or white stripes right angles to the drilling axis that serves to indicate whether the assembly is twisted Loads a) Lay Lines - Deal with the two kinds of loading which are the radial and thrust 89) A hose must have a 2-4% slack allowance in installation so the hose Sliding bearings won’t over extend in operation - The journal of a sliding bearing operates in a bearing box, a bearing 90) Used to support the journals of shaft and axles bushing or directly in the bearing body a) Bearings Anti friction bearings 91) Bearings for pivot journals and designed to accept forces in - Consists of the outer and inner raceway, the rolling element and longitudinal direction usually a rolling element cage (*PARTS) a) Pivot or axial bearings Types of Anti friction bearings 92) Bearing for supporting journals and designed to accept forces at right 1. Roller Bearings – are used if the occurring stresses are too - angles too the drilling axis. severe for ball bearings a) Journal or roller bearings 2. Ball Bearings- have a very low starting resistance and are 93) Bearings used with the combination of thrust and radial load suitable for high rotation speeds a) Tapered roller bearings 3. Radial Bearings- can accept forces that act radially to the shaft 94) A requirement for the long working life of bearings axis a) Adequate Lubrication 4. Axial or longitudinal Bearings- accept forces that act in the direction of the axis of the shaft 95) A type of bearing that is used where limited spaces are available Transmissions - Needle Bearing Chains 1.) Bearings that accept forces that act radially to the shaft axis - Provides strong, flexible and positive connections and are generally - Radial Bearings used wherever it becomes necessary to change the direction of 2.) Provides string, flexible and positive connections and used control runs in systems where considerable force is exerted wherever necessary to change the direction of control Chain Drives - Chains - Are suitable for pop slop power transmission with large spaces between 3.) Change of directions in chains are achieved with the use of axles when cog wheels are not available to decrease the size - Chain wheels of the spaces 4.) Power transmission for trim is achieved via Roller Chains - Chain Drive - The turnable rolls of roller chains along the flanks on the chain wheel 5.) The revolving chain is tensioned by teeth. The number of teeth should not be smaller than 12. - Chain tightener Gear Chains - Have cogged lugs which engage into the gaps between the teeth of the 6.) Used to transfer forces into cables an push rods chain wheel. The number of teeth should not be smaller than 17 - Cable Quadrants with regard to wear 7.) Used to transmit swinging or rotating movements Couplings - Torque tube transmission - Are used to connect two shafts with each other If not in use, a chain must not be put on a flat surface. It should A. Solid Couplings be carefully coiled and wrapped in a grease paper - It is used for a rigid connection between two shafts to achieved 8.) Used to prevent the gears from jamming and making contact on - Types of Couplings both sides of their teeth simultaneously. 1. Sleeve couplings - Backlash Consists of two cast iron sleeves which are fixed to the shaft ends by screws Control cables in aircraft are often 2. Disk Couplings 3/32 – 7x7(flexible cable) or 1/8 – 7x19(Extra flexible cable) Two disks are fitted to the shaft ends by screws B. Movable Couplings 9.) a cable which consist of a tension wire wound either with a - Comprise expansion couplings, hinge coupling and elastic couplings. continuous left or right hand helix winding They are used if the shafts are not in alignment or if the position of the shafts changes during operation - Teleflex control cables A. Extension Couplings 10.) A cable which is a short run, lightly loaded type of control that is Allow a small longitudinal movement of shaft in relation to other made of non-corrodible steel wire designed for “pull” operations One kind of this coupling is called the claw coupling which is also only. used as disconnectable couplings - Bowden cables B. Hinge Couplings Comprise cross links, dry disk joins and ball and socket joints They are Heat treatment of Al. Rivets used in cases where the direction of the axes of the shafts Solution Annealing linked to the couplings change in a certain angle - The material is annealed at 495 degrees for a certain time and after C. Cross links that it is quenched at 20 degrees cold water. The material can be deformed without high loads and crystal damage Are suitable to transfer stronger forces, such as in automobiles - All rivets 3.1324, 2017,2017 A and 2024- alloys must be stored at -18 D. Dry Disk Joints degrees. At this temperature, the rivets can be stored up to 7 days and Consist of elastic clutch disks, each connected to a flange at the at -20 degrees, it can be stored up to 20 days end of the shaft. The angle around which is the shaft axes can Taper Lok fastener rotate is 8 degrees - Is a tapered bolt with a threaded end and a self locking nut. It also Gear Drives includes it’s own washer. It transfer rotational movement at low speeds without sleep. Lock bolts Power Transmissions - Is a two piece assembly that consists of A pin with a protruding or Power transmission in parallel shafts is achieved by spur wheels or counter sink head and a collar that is waged on to the locking grooves by a cog wheel with internal toothing and pinion. on the pin shank to secure the pin when it is installed In case of shafts with axes that stand perpendicular to each other, Riv nuts power transmission is achieved by Bevel Gears - Is a combination of a rivet and nut, resembling a hollow rivet with If the axes are crossing, power transmissions is achieved by a threads inside its shank worm and worm gear by a Helical Gear Bearings Spur Gears - Are used to support journals of shafts and axles - May have straight teeth, slanting teeth and herring bone teeth. Types of bearings A. Slanting teeth 1. Pivot or Axial bearings – it is the bearing that is used for pivot Operate much more silently than wheels with straight teeth, journals, which are designed to accept forces in a longitudinal because at all times, several teeth are engaged direction B. Herringbone Teeth The axial forces eliminate each other. Because of this, herringbone gears are used for the transmission of large forces Gear Units - Transmit the rotational speed of the driving engine in a way that the shaft or spindle turns with the required rotation speed. It can also change the direction of the rotational movement Helical Gears - Are only suitable for the transfer of small forces, because the flanks of the teeth contact in only one spot Worm Gears - Large transmissions can be achieved with worm drives when the drive is created by the worm. When a one- toothed worm turns once, the respective worm gear moves only the distance of one tooth Bevel Gears - Bevel gears that operate together are two conical surfaces which roll without slipping because of their tooth system Toothed wheel Gears - There are two types of variable gears which are the stepped transmission gears and the driving key type transmission gears A. Stepped transmission Gears The wheels of variable gears are engaged and reach the desired rotational speed by moving them sideways. B. Driving key type Gears Can only be used to transmit small forces at low rotational speed. It does not need much space and can change gears during operations Friction Gear - Has a simple set up. The driving friction wheel is movable, so that the rotation speed of the driven friction disk is infinitely variable Coney Pulley Drive - Is suitable for transmission of smaller forces at high rotational speed. Transmission Component Control Mechanism A. Cables Are the primary transmission components in airplane without fly by wire system. It is versatile, offer movement free of play, problem- free transmission on a weight saving basis and can thus be routed into almost every area via guiding pulleys Cables used in airplane construction has a minimum tensile strength of 1200N/mm2 at a breaking elongation of 2 or 7% B. Push rods Are used to operate rudders, auxiliary rudders, flaps etc. It can transmit pulling and pushing forces C. Quadrants Forces are transferred to cable via cable quadrants and the forces of the cables are also transmitted to push rods via cable quadrants D. Torque Tube Transmissions Swinging or rotating movements are transmitted by Torque tube transmissions Heat treatment of Al. Rivets - The material is annealed at 495 degrees for a certain 18. Are used to connect two shafts with each other time and after that it is quenched at 20 degrees cold Couplings water. The material can be deformed without high loads and crystal damage 19. It is used for a rigid connection between two shafts to achieved - All rivets 3.1324, 2017,2017 A and 2024- alloys must be Solid Couplings stored at -18 degrees. At this temperature, the rivets Types of Couplings can be stored up to 7 days and at -20 degrees, it can be 20. Consists of two cast iron sleeves which are fixed to the shaft stored up to 20 days ends by screws Solution Annealing Sleeve couplings 21. Two disks are fitted to the shaft ends by screws 1. Is a tapered bolt with a threaded end and a self locking nut. It Disk Couplings also includes it’s own washer. 22. Comprise expansion couplings, hinge coupling and elastic Taper Lok fastener couplings. They are used if the shafts are not in alignment or 2. Is a two piece assembly that consists of A pin with a protruding if the position of the shafts changes during operation or counter sink head and a collar that is waged on to the locking Movable Couplings grooves on the pin shank to secure the pin when it is installed 23. Allow a small longitudinal movement of shaft in relation to Lock bolts other Extension Couplings 3. Is a combination of a rivet and nut, resembling a hollow rivet with threads inside its shank One kind of this coupling is called the claw coupling which is also used as Riv nuts disconnectable couplings 4. Are used to support journals of shafts and axles Bearings 24. Comprise cross links, dry disk joins and ball and socket joints They are used in cases where the direction of the axes of the Types of bearings shafts linked to the couplings change in a certain angle 5. it is the bearing that is used for pivot journals, which are Hinge Couplings designed to accept forces in a longitudinal direction 25. Are suitable to transfer stronger forces, such as in automobiles Pivot or Axial bearings Cross links 26. Consist of elastic clutch disks, each connected to a flange at the 6. it is the bearing that is used for supporting journals, which are end of the shaft. The angle around which is the shaft axes can designed to accept forces at right angles to the drilling axis rotate is 8 degrees Journal or Roller bearings Dry Disk Joints 7. Deal with the two kinds of loading which are the radial and 27. It transfer rotational movement at low speeds without sleep. thrust Gear Drives Loads 28. Power transmission in parallel shafts is achieved by spur wheels 8. The journal of a sliding bearing operates in a bearing box, a or by a cog wheel with internal toothing and pinion. bearing bushing or directly in the bearing body Power Transmissions Sliding bearings 29. In case of shafts with axes that stand perpendicular to each 9. Consists of the outer and inner raceway, the rolling element other, power transmission is achieved by and usually a rolling element cage (*PARTS) Bevel Gears Anti friction bearings 30. If the axes are crossing, power transmissions is achieved by a worm and worm gear by a Types of Anti friction bearings Helical Gear 10. are used if the occurring stresses are too severe for ball 31. May have straight teeth, slanting teeth and herring bone bearings teeth. Roller Bearings Spur Gears 11. have a very low starting resistance and are suitable for high rotation speeds 32. Operate much more silently than wheels with straight Ball Bearings teeth, because at all times, several teeth are engaged 12. can accept forces that act radially to the shaft axis Slanting teeth Radial Bearings 33. The axial forces eliminate each other. Because of this, 13. accept forces that act in the direction of the axis of the herringbone gears are used for the transmission of large forces shaft Herringbone Teeth Axial or longitudinal Bearings Transmissions 34. Transmit the rotational speed of the driving engine in a way that 14. Provides strong, flexible and positive connections and are the shaft or spindle turns with the required rotation speed. It generally used wherever it becomes necessary to change the can also change the direction of the rotational movement direction of control runs in systems where considerable force is Gear Units exerted Chains 15. Are suitable for pop slop power transmission with large spaces 35. Are only suitable for the transfer of small forces, because the between axles when cog wheels are not available to decrease flanks of the teeth contact in only one spot the size of the spaces Helical Gears Chain Drives 36. Large transmissions can be achieved with worm drives when the 16. The turnable rolls of roller chains along the flanks on the chain drive is created by the worm. When a one- toothed worm turns wheel teeth. The number of teeth should not be smaller than once, the respective worm gear moves only the distance of one 12. tooth Roller Chains Worm Gears 17. Have cogged lugs which engage into the gaps between the teeth of the chain wheel. The number of teeth should not be smaller 37. Bevel gears that operate together are two conical surfaces which than 17 with regard to wear roll without slipping because of their tooth system Gear Chains Bevel Gears  38. There are two types of variable gears which are the stepped transmission gears and the driving key type transmission gears Toothed wheel Gears 39. The wheels of variable gears are engaged and reach the desired rotational speed by moving them sideways. Stepped transmission Gears 40. Can only be used to transmit small forces at low rotational speed. It does not need much space and can change gears during operations Driving key type Gears 41. Has a simple set up. The driving friction wheel is movable, so that the rotation speed of the driven friction disk is infinitely variable Friction Gear 42. Is suitable for transmission of smaller forces at high rotational speed. Coney Pulley Drive Transmission Component Control Mechanism 43. Are the primary transmission components in airplane without fly by wire system. It is versatile, offer movement free of play, problem- free transmission on a weight saving basis and can thus be routed into almost every area via guiding pulleys Cables 44. Cables used in airplane construction has a minimum tensile strength of 1200N/mm2 at a breaking elongation of 2 or 7% 45. Are used to operate rudders, auxiliary rudders, flaps etc. It can transmit pulling and pushing forces Push rods 46. Forces are transferred to cable via cable quadrants and the forces of the cables are also transmitted to push rods via cable quadrants Quadrants 47. Swinging or rotating movements are transmitted by Torque tube transmissions airbus two type of wire Torque Tube Transmissions US WIRE TYPE METRIC WIRE TYPE 48. Customer wire number 9000 to 9999 49. service bulletin wire number 8000-8999 50. shielded wire number 7000-7999 51. built to a300/a310 series US wire type 52. built into consecutive airbus series. smaller cross section metric wire types 53. HOW do you connect connecting lines? must be able to connect to the connections exactly matching axis and be free of tension to maintain seal. steel lines(pipes and unions)- pressure lines, longer life expectancy 54. cant be safetied by any other practical means turnbuckle no more than 3 threads exposed turnbuckle dont lubricate turnbuckle prevent electromagnetic field from entering escaping wire Shielding short circuit in wire harness with fluid causes carbon arc tracking/ insulation flashover