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Questions and Answers
Which hardwood is known for its high oils and resistance to acids and alkalis, primarily used in outdoor furniture?
Which hardwood is known for its high oils and resistance to acids and alkalis, primarily used in outdoor furniture?
Softwoods are generally more durable and expensive compared to hardwoods.
Softwoods are generally more durable and expensive compared to hardwoods.
False
What is the process of removing moisture from timber to increase its stability and strength?
What is the process of removing moisture from timber to increase its stability and strength?
Seasoning
_____ is a method used to prevent insect attack in wood by forcing copper into the material.
_____ is a method used to prevent insect attack in wood by forcing copper into the material.
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Match the following types of timber with their characteristics:
Match the following types of timber with their characteristics:
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Which polymer type cannot be reused after curing?
Which polymer type cannot be reused after curing?
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Borosilicate glass has a high coefficient of thermal expansion.
Borosilicate glass has a high coefficient of thermal expansion.
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Name a type of polymer used in food containers.
Name a type of polymer used in food containers.
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_____ is a high-strength thermosetting polymer used in coatings and adhesives.
_____ is a high-strength thermosetting polymer used in coatings and adhesives.
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Match the following materials with their properties or uses:
Match the following materials with their properties or uses:
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Which of the following is NOT a characteristic of thermoplastics?
Which of the following is NOT a characteristic of thermoplastics?
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E-textiles integrate hard electronics to provide functionality.
E-textiles integrate hard electronics to provide functionality.
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What type of materials respond to external factors?
What type of materials respond to external factors?
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Which of the following statements about electrical insulators is true?
Which of the following statements about electrical insulators is true?
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Thermal insulators facilitate the transfer of heat.
Thermal insulators facilitate the transfer of heat.
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What is the main purpose of additives in polymers?
What is the main purpose of additives in polymers?
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A material's ability to withstand environmental attack and decay is known as its __________ resistance.
A material's ability to withstand environmental attack and decay is known as its __________ resistance.
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Which of the following factors is NOT considered when selecting materials?
Which of the following factors is NOT considered when selecting materials?
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Modern materials can include those that are self-healing.
Modern materials can include those that are self-healing.
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What must materials be assessed for to ensure they are fit for their purpose?
What must materials be assessed for to ensure they are fit for their purpose?
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Match the following types of materials with their descriptions:
Match the following types of materials with their descriptions:
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To reduce costs, materials should ideally provide __________ efficiency.
To reduce costs, materials should ideally provide __________ efficiency.
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Which of the following represents an environmental consideration when selecting materials?
Which of the following represents an environmental consideration when selecting materials?
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Which of the following metals is an alloy of copper and zinc?
Which of the following metals is an alloy of copper and zinc?
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Stainless steel is resistant to corrosion and can be made magnetic.
Stainless steel is resistant to corrosion and can be made magnetic.
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What process is used to break down large hydrocarbon molecules in crude oil?
What process is used to break down large hydrocarbon molecules in crude oil?
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___ is an alloy of Aluminium that is lightweight and hard, commonly used in aircraft.
___ is an alloy of Aluminium that is lightweight and hard, commonly used in aircraft.
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Match the following metals with their properties:
Match the following metals with their properties:
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Which alloy contains copper and has a higher melting point than brass?
Which alloy contains copper and has a higher melting point than brass?
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High carbon steel is known for its ductility and corrosion resistance.
High carbon steel is known for its ductility and corrosion resistance.
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What is the main characteristic of manufactured boards compared to natural wood?
What is the main characteristic of manufactured boards compared to natural wood?
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Bronze is generally ___% more dense than stainless steel.
Bronze is generally ___% more dense than stainless steel.
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Which metal is used extensively in electrical applications due to its conductivity?
Which metal is used extensively in electrical applications due to its conductivity?
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Which of the following materials can return to their original shape when a force is removed?
Which of the following materials can return to their original shape when a force is removed?
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Phosphorescent materials change color in response to temperature changes.
Phosphorescent materials change color in response to temperature changes.
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What property indicates a material's ability to withstand being crushed by pushing forces?
What property indicates a material's ability to withstand being crushed by pushing forces?
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Materials that can be permanently deformed and retain that shape demonstrate __________.
Materials that can be permanently deformed and retain that shape demonstrate __________.
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Match the property of materials with its definition:
Match the property of materials with its definition:
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Which of the following types of materials respond to changes in light?
Which of the following types of materials respond to changes in light?
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Electrochromic materials change color when subjected to changes in electrical charge.
Electrochromic materials change color when subjected to changes in electrical charge.
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What is the property that compares the weight of a structure to the weight it can support without fracture?
What is the property that compares the weight of a structure to the weight it can support without fracture?
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__________ materials respond to changes in pressure by changing color.
__________ materials respond to changes in pressure by changing color.
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Match the modern materials to their characteristic response:
Match the modern materials to their characteristic response:
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Study Notes
Smelting Metals
- Impure metals (ores) need testing before application—variations in properties and appearance.
Refining Crude Oil
- Fractional distillation—heating crude oil separates different hydrocarbons.
- Cracking—breaks down large hydrocarbon molecules into smaller ones.
Metals - Alloys
- Brass—copper and zinc alloy, sonorous, used in locks, gears, door handles, and more.
- Bronze—copper alloy, higher melting point than brass, highly ductile, denser than stainless steel, used in sculptures and bearings.
- Duralumin—aluminum alloy, lightweight, hard, used in aircraft.
- Bauxite—aluminum alloy, low conductivity, hard and abrasive, refined and smelted via electrolysis.
Metals - Ferrous
- Mild steel—tough, ductile, malleable, poor corrosion resistance, used in general construction/cutting tools.
- High carbon steel—wear-resistant, brittle, poor corrosion resistance, used in hand/machine tools.
- Stainless steel—magnetic, ductile, corrosion-resistant, used in cutlery and surgical instruments.
- Cast iron—heavy, rigid, easily machined, used in old lampposts and art pieces.
Metals - Non-Ferrous
- Aluminum—soft, low strength, high conductivity, alloyed easily, used in various metal products.
- Zinc—corrosion-resistant, used to galvanize other metals.
- Tin—corrosion-resistant, used to make tins.
- Copper—pure form is soft, malleable, corrosion-resistant, thermally and electrically conductive, used in wires, etc.
- Tungsten—toughest material, super dense, resistant to corrosion, melting point of 3422°C, used in drill bits and tools.
Woods - Manufactured Boards
- Made from recycled woods, available in large sheets—consistent properties; available pre-finished.
- Engineered boards (cement bonded particle board)
- Laminated (including plywood)—strong, cannot split, marine plywood is water resistant and thinner than regular plywood.
- Compressed (including MDF)—bonded with resin, similar to plywood but larger chunks.
- Wood veneers—stuck on manufactured boards to enhance aesthetics.
Woods - Hardwoods
- Hardwoods—slow-growing, require more land; more expensive but often favored for aesthetics.
- Oak—resistant to rot, long-lasting, strong, durable, corrodes steel—used in construction, furniture, ship building, etc.
- Ash—springy, elastic, shock-resistant—mostly in sports equipment, tool handles.
- Birch—uniform, even texture, low cost, least resilient against insects and rot; used in veneers, plywood, furniture, cabinets, etc.
- Mahogany—endangered species—aesthetically pleasing, stable, highly prized; used in vintage furniture.
- Beech—flexible, tough, odourless, resistant to abrasion, very hard to chip—used in bowls and toys.
- Teak—naturally high in oils—high resistance to acids and alkalis—used mainly in outdoor furniture and chairs.
Woods - Softwoods
- Fast-growth means low cost, mostly lightweight; less seasoning required.
- Douglas Fir—tough, cheap, strong—used in construction, decking, and instruments, etc
- Redwood—grow quickly, great strength-to-weight ratio—used in construction.
- Spruce—great strength-to-weight ratio—used in early aircraft (WWI and II).
- Cedar—high oil content, decay- and insect-resistant—used in outdoor furniture, fencing, decking, etc.
- Larch—high resin content—used in veneers, fence posts, furniture, and boats.
Woods - Random Memorisation
- Rough-sawn timber—cheapest, used most in construction/outdoors.
- Planed timber—made using a planer and thicknesser, smaller and more expensive.
- Natural timbers—most wood sold as boards and square sections—rough sawn or PSE or PAR.
- PSE timber—one square edge.
- PAR timber—square on all sides.
- Wood grain—structure of wood grain affects workability and cost.
- Wood structure—wood like group of straws.
- Anisotropic—material easy to break in one direction, hard in other.
Ceramics
- Used in aerospace, electronics, and biomedicine—made from same ingredients. Superior properties than unrefined ceramics.
- Borosilicate glass—low thermal expansion coefficient.
- Silicon carbide—can be combined with steel, high temp., incredibly hard and hard-wearing.
- Tungsten carbide—high melting point, twice as stiff and dense as steel—very high hardness.
Polymers - Thermosetting
- Cannot be reused, strongly linked monomers. Often hard and durable. Made from crude oil.
- Urea formaldehyde—hard, inexpensive, brittle—used as wood glue.
- Epoxy resin—high strength, stiff, brittle, chemical and electrical resistance, temp. resistance—used as coatings, LEDs, etc
- Phenol formaldehyde—high working temperature, used as laminate sheets, coatings on metals.
- Polyester resin—often bonded with other materials, lower cost than other resins, used in industrial coatings, boat building.
Polymers - Thermoplastic/Thermoforming
- Can be reused, loosely linked monomers: recyclable, remouldable. Made from crude oil.
- Polyethylene (PE)—120-130°C melting point, flexible, translucent, weatherproof, tough, low cost, food containers, bottles, etc.
- Polyamide (PA)—220-260°C melting point, high wear resistance, high thermal stability, good strength/hardness--textiles, sportswear, automotive parts.
- ABS—good resistance to med. temps, hard, tough, antistatic, good resistance—gardening tools, medical applications, pipes, etc.
- Polypropylene (PP)—poor UV resistance, translucent, rigid, light, excellent chemical resistance—plastic packaging, machinery parts, carpeting, ropes, etc.
- PVC—good UV resistance, excellent chemical resistance, glue-able, weldable, bendable, machinable, stiff—medical tubing, window frames, etc.
- Polyvinyl chloride (PVC)—very light, high tensile strength, hard, stiff—used in bottles, containers and chemical storage, etc
- Acrylic—weather resistant, difficult to recycle, corrosion resistant, electrical insulator—used in lenses, replacements for glass, display products indoor/outdoor signage.
Modern Materials
- E-textiles—materials that eliminate the need for wires and hard electronics, used in sensors, thermochromic displays, etc.
- Super alloys—extreme applications—turbine engines, marine, etc.
- High-Performance Alloys—unique alloys to meet specific needs—used in various industries.
- Bioplastics—plastics from natural sources (fossil fuels, corn, cane, sugar, potatoes).
- Nanocrystalline/Nanocomposites—materials with crystalline properties/added to improve other materials' properties—cutting tools, etc.
Smart Materials
- Respond to external factors (heat change, electrical charge, change in pressure).
- Thermochromic—respond to temp. change (colour change).
- Phosphorescent—respond to light changes (light output change).
- Photochromic—respond to light changes (colour change).
- Electrochromic—respond to current changes (colour change).
- Piezochromic—respond to pressure changes (colour change).
- Solvatochromic—respond to dissolving changes (colour change).
- Shape Memory Alloys—deform when cold, return to original when heated.
- Shape Memory Polymers—deform when heated/pressure applied.
Properties
- Compressive strength—resists being crushed.
- Tensile strength—resists stretching/pulling.
- Stiffness—resists bending.
- Hardness—resists wear/abrasion.
- Durability—resists weathering/damage.
- Impact resistance—absorbs impact without fracture.
- Plasticity—ability to be permanently deformed and retain that shape.
- Elasticity—ability to deform but return to original shape.
- Malleability—ability to be deformed.
- Ductility—ability to be drawn into wires.
- Density—mass per unit volume.
- Strength-to-weight ratio—comparison of strength and weight.
- Flammability—how a material burns after ignition
- Electrical Conductivity—whether it is an electrical conductor/insulator
- Thermal Conductivity—a conductor/insulator of thermal energy flow.
- Corrosion/degradation resistance—material's ability to withstand environmental attack.
- Additives—enhance polymer properties (e.g., fire retardant, antistatic, biodegradability).
Material and Component Considerations
- Materials need testing for profitability; being fit for purpose; desirable characteristics and properties.
- Aesthetics—feel, color, texture, shape, longevity, form, and user selection.
- Reducing costs/higher efficiency—specialized/compatible materials; storage/handling.
- Environmental considerations—social, ethical, economical, and environmental impacts.
Mechanisms
- Efficient mechanisms transfer power without adding or subtracting.
- Efficiency = (Actual Mechanical Efficiency/Ideal Mechanical Advantage) x 100%.
- Efficiency = (Output Power/Input Power) x 100%.
- Actual Mechanical Advantage = (Measured Output Force/Input Force).
Mechanisms - Types
- Motion—rotary, linear, reciprocating, oscillating
- Mechanical Advantage-Load/Effort
- Epicyclic gears—used in cars, engines, gearboxes, drills, motors—three gear ratios.
- Gears—idler gear, mitre, chain & sprocket, belt & pulley, worm drive, screw thread, rack & pinion.
Bearings and Lubrication
- Bearings—components supporting moving parts.
- Planned bearing, tapered bearing, ball bearing, fluid bearing, thrust bearing.
- Drive shaft—requires two contact points.
- Axial loading—force along an axis.
- Radial loads—act at right angles to the shaft.
Systems
- Systems generate/control/change motion.
- Force—often called effort.
- Output force—often called load
- Mechanical advantage = (distance moved by effort / distance moved by load).
- Mechanical advantage = (input arm length / output arm length).
Linkages
- Bell crank
- Crank and slider
- Peg and slot.
Joining Processes
- Joining Woods—difficult with high oil woods.
- Adhesives, joints, and fittings.
- Framing—adding, removing material.
- Laminating—creating curves and increasing surface area.
- Tanalising—prevents insect attack, forces copper sulphate into wood.
Definitions I Didn't Know
- CADD—computer-aided design and drafting (designs converted into technical drawings).
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Description
Explore the essential concepts of metallurgy, including smelting, refining, and the properties of different metal alloys. This quiz covers key terms and processes related to ferrous and non-ferrous metals used in various applications. Test your knowledge on the significance of metals in industry and everyday life.
