Non Ferrious Revision

Questions and Answers

What is the most suitable mixture for a salt bath operation?

50% sodium nitrate and 50% nitrate of soda.

70% sodium chlorate and 30% sodium nitrate.

20% nitrate of soda and 80% sodium nitrate.

90% nitrate of soda and 10% sodium nitrate. (correct)

How many times can clad alloy be heat treated?

As many times as required.

Up to 5 times.

3 times. (correct)

Once only.

What does the symbol 'W' on a material indicate?

It has been solution treated and will respond effectively to precipitation treatment. (correct)

It is specifically for use on aircraft fuselage.

It should be used in high-stress applications.

It is suitable for workshop use only.

Which conditions are best to minimize creep in a particular metal material?

Low stress and low temperature. Signup and view all the answers

Which of the following mixtures is not suitable for a salt bath operation?

20% nitrate of soda and 80% sodium nitrate. Signup and view all the answers

Which of the following statements about clad alloy heat treatment is true?

It generally benefits from up to 3 heat treatments. Signup and view all the answers

What is the main purpose of solution treatment indicated by the symbol 'W'?

To prepare the material for precipitation treatment. Signup and view all the answers

Which combination of conditions would likely promote creep in metal materials?

High stress and high temperature. Signup and view all the answers

What is the effect of precipitation heat treatment on aluminium?

It speeds up age hardening process. Signup and view all the answers

What happens to aluminium when it is exposed to air?

It oxidises and becomes electrically insulated. Signup and view all the answers

What care should be taken with 2024-T3 aluminium alloy?

Do not scratch or make nicks in it. Signup and view all the answers

What is the composition of silver solder?

Tin, lead, silver, and antimony. Signup and view all the answers

What occurs if an aluminium alloy is not quenched after heat treatment?

It becomes brittle. Signup and view all the answers

What additional benefit does anodizing provide to alloy metal aside from corrosion protection?

Makes a good surface for paint to adhere to. Signup and view all the answers

If caustic soda turns a material black, what does this indicate?

It is an aluminium alloy. Signup and view all the answers

What chemical is utilized to identify aluminium alloys?

Caustic soda. Signup and view all the answers

How resistant to corrosion is pure aluminium?

Highly resistant to corrosion. Signup and view all the answers

What effect does precipitation treating have on the strength of metal?

It makes the metal harder and stronger. Signup and view all the answers

In the code 2024-TH6, which part represents the percentage of the alloying element?

The number 20. Signup and view all the answers

Which aluminium alloy is primarily alloyed with magnesium?

<ol start="5025"> <li></li> </ol> Signup and view all the answers

How is heat treatment indicated on a British aluminium alloy?

By a letter and number code. Signup and view all the answers

What can non-heat treatable materials be hardened by?

By strain hardening or cold working. Signup and view all the answers

Which metal is known as an aluminium silicon alloy primarily used for casting?

Alpax. Signup and view all the answers

The purpose of joggling aircraft skin is to achieve what outcome?

Provide smooth airflow at faying surfaces. Signup and view all the answers

What does the British system of heat treatment codes primarily consist of?

A series of letters. Signup and view all the answers

When comparing the markings on L162 and L172 aluminium alloys, which statement is true?

Sheet one is more ductile than sheet two. Signup and view all the answers

The main effect of cold working a material is to reduce which characteristic?

Wear of manufacturing tools. Signup and view all the answers

For optimal storage, sheet metal should be positioned how?

On its edge in racks to prevent scratches. Signup and view all the answers

Clad aluminium alloy (alclad) typically has a coating thickness that is what percentage of the alloy thickness?

5% Signup and view all the answers

What is the primary metal found in monel?

Nickel. Signup and view all the answers

What characteristic makes nickel chromium suitable for use in exhaust systems?

It is corrosion resistant and has a low thermal expansion coefficient. Signup and view all the answers

Titanium alloys are known for which of the following properties?

Having a low density and high strength-to-weight ratio. Signup and view all the answers

In the designation of the 2017-T36 aluminium alloy, which number indicates the primary alloying agent?

<ol start="2"> <li></li> </ol> Signup and view all the answers

Why are clad aluminium alloys preferred in aviation applications?

They demonstrate lower susceptibility to corrosion. Signup and view all the answers

Non-heat treatable aluminium alloys can be modified how?

By strain hardening. Signup and view all the answers

After solution treatment, how many additional times can aluminium alloy be treated?

Twice. Signup and view all the answers

Following solution treatment, when can aluminium alloy be placed into service?

After 24 hours. Signup and view all the answers

What is the correct bonding material for Tungsten Carbide?

Cobalt Signup and view all the answers

Which statement regarding grain size is true?

Large grain size is attributed to slow cooling rates and will give less tensile strength. Signup and view all the answers

What is an alloy characterized by?

A combination of two or more metallic materials. Signup and view all the answers

What does the T4 designation in 2024-T4 indicate?

The material is solution treated and naturally aged. Signup and view all the answers

What does silver solder typically consist of?

Copper, Zinc, and Silver Signup and view all the answers

What defines fatigue in engineering terms?

Cyclic stressing of a part. Signup and view all the answers

Which characteristic describes malleable materials?

Easily forged. Signup and view all the answers

Why is stop drilling performed at the end of a crack?

To stop the crack from propagating. Signup and view all the answers

What is the composition of Monel metal?

66% Nickel and 33% Copper Signup and view all the answers

Which of the following describes ductility?

The ability to be drawn into wires. Signup and view all the answers

What does the code 1285 in the IADS coding system indicate?

99.85% pure aluminium Signup and view all the answers

Which of the following materials is highly ductile?

Copper Signup and view all the answers

When malleability and ductility are combined, which best describes a material?

Easily shaped and stretched. Signup and view all the answers

Which characteristic is associated with creep?

Gradual deformation under constant load. Signup and view all the answers

What is the primary disadvantage of using pure aluminium compared to aluminium alloys in applications like aircraft?

It is weaker. Signup and view all the answers

Which of the following statements correctly describes age hardening in aluminium alloys?

Age hardening is not performed for aluminium. Signup and view all the answers

What is the reason for removing the oxide layer when buffing aluminium alloy?

To improve aesthetics. Signup and view all the answers

Which property of clad aluminium allows it to be preferred over pure aluminium for construction purposes?

Higher toughness. Signup and view all the answers

Which of the following characteristics correctly identifies the surface oxide film on aluminium?

It is strong and non-porous. Signup and view all the answers

When recognising magnesium alloys used in aircraft, which surface appearance is most indicative?

Yellowish due to protective treatment. Signup and view all the answers

What is the defining feature of cladding applied to aluminium?

A layer of aluminium over a stronger substrate. Signup and view all the answers

For deep cold forming of a material, which property is crucial?

Malleability of the material. Signup and view all the answers

Which option best describes why clad alloys are typically preferred in aircraft materials?

They provide enhanced strength due to the clad layers. Signup and view all the answers

What process is referred to when forming a pure layer of aluminium over an aluminium alloy?

Cladding. Signup and view all the answers

What distinguishes titanium alloys in terms of identifying them on a grinding wheel?

They generate white sparks. Signup and view all the answers

What is the critical aspect of heat treatment in metalworking?

Both temperature and cooling method must be managed. Signup and view all the answers

What type of treatment can retouch aluminium alloys?

Alocrom treatment. Signup and view all the answers

What does the impact testing technique measure?

The toughness of a material. Signup and view all the answers

In the Brinell hardness test, which measurement is used to indicate hardness?

Diameter of the indentation. Signup and view all the answers

What is the purpose of an S-N curve in material testing?

To evaluate fatigue life. Signup and view all the answers

What characteristic defines a fusible material?

Its capacity to melt when heated. Signup and view all the answers

Which of the following best describes brittleness?

The property to not deform before cracking. Signup and view all the answers

What indicates the proof stress of a material?

A small amount of permanent set occurs. Signup and view all the answers

Young's Modulus measures which property of a material?

The stiffness of a material. Signup and view all the answers

According to Hooke's Law, elastic strain is directly proportional to what?

Stress. Signup and view all the answers

What is the S.I. unit for strain?

No units. Signup and view all the answers

How is stress calculated for a material?

Load / Area. Signup and view all the answers

A material's yield strength refers to its ability to:

Resist permanent deformation. Signup and view all the answers

Which type of test stretches material until it breaks?

Tensile Testing. Signup and view all the answers

What is the result of increasing the temperature of a ductile material?

Decreased yield strength. Signup and view all the answers

What phenomena occurs when a material undergoes necking?

It begins to fracture. Signup and view all the answers

Study Notes

Salt Bath Operations

Optimal mixture for a salt bath: 90% nitrate of soda and 10% sodium nitrate.

Clad Alloy Treatment

Clad alloy can be heat treated up to 3 times.

Material Symbols

The symbol 'W' indicates a material has been solution treated and will respond to precipitation treatment.

Creep Minimization

Best conditions to minimize creep: low stress and low temperature.

Precipitation Heat Treatment

In aluminium, precipitation heat treatment speeds up the age hardening process.

Aluminium Oxidation

Aluminium exposed to air oxidizes, becoming electrically insulated.

2024-T3 Alloy Care

Handle 2024-T3 carefully to avoid scratches and nicks due to its low fatigue resistance.

Silver Solder Composition

Silver solder contains tin, lead, silver, and antimony.

After Heat Treatment Effects

An aluminium alloy not quenched in time will become brittle due to copper precipitation.

Anodizing Benefits

Anodizing helps create a good surface for paint adhesion.

Caustic Soda Reaction

Caustic soda turns aluminium alloy black, while pure aluminium turns white.

Identifying Aluminium Alloys

Use caustic soda to identify aluminium alloys based on the color change.

Aluminium Corrosion Resistance

Pure aluminium is highly resistant to corrosion.

Precipitation Treatment Results

Precipitation treatment makes metals harder, stronger, and less ductile.

Alloy Composition Numbering

In alloy code 2024-TH6, '20' indicates the percentage of the alloying element.

Magnesium Alloy Numbering

Magnesium alloyed primarily is numbered as 5025.

British Heat Treatment Codes

Heat treatment is indicated using a letter code in British aluminium alloys.

Non-Heat Treatable Alloys

Non-heat treatable materials can be hardened through strain hardening or cold working.

Aluminium Alloy Casting

Alpax is an aluminium silicon alloy primarily used for casting.

Aircraft Skin Jogging

Joggling on aircraft skin provides smooth airflow at faying surfaces.

British System of Codes

The British system for heat treatment consists of a series of letters.

Sheet Metal Storage

Store sheet metal on its edge in racks to prevent scratching.

Clad Aluminium Alloy Coating

Clad aluminium has a pure aluminium coating of 5% of alloy thickness.

Monel Composition

Monel is primarily composed of nickel.

BS T51 Tube Specification

A tube complying with BS T51 is categorized as a high pressure seamless copper tube.

Nickel Chromium Use

Nickel chromium is favored in exhaust systems for its corrosion resistance and low expansion coefficient.

Titanium Alloys

Titanium alloys are recognized for their high strength-to-weight ratio.

Clad Alloy Advantages

Clad alloy is tougher than pure aluminium, enhancing performance.

Aluminium in Aircraft

Aluminium alloys replace pure aluminium in aircraft due to their superior strength.

Magnesium Alloy Appearance

Magnesium alloys typically have a yellowish surface from protective treatments.

Aging in Aluminium

Aluminium does not undergo age hardening like other alloys due to a lack of alloying elements.

Definition of Alclad

Alclad is duralumin coated with a layer of pure aluminium.

Oxide Film Characteristics

The oxide film on aluminium is hard yet non-porous.

Cladding Process

Cladding involves forming a pure layer of aluminium over an aluminium alloy.

Titanium Identification

Titanium can be identified by white sparks when ground.

Heat Treatment Process

Effective heat treatment requires careful control of temperature, heating, and cooling methods.

Aluminium Alloy Re-treatment

Re-treatment of aluminium alloys is commonly performed through alocrom treatment.

Titanium Strength Comparison

Titanium is generally stronger than aluminium but not necessarily as strong as steel.

Malleability of Materials

Malleable materials are easy to forge, while ductility relates to stretching capabilities.

Deep Cold Forming Requirements

Malleability is essential for materials undergoing deep cold forming operations.

Salt Bath Heating Restrictions

Magnesium alloy must not be heated in a salt bath to avoid adverse reactions.

Colour Code Significance

The colour code on sheet metal indicates the material specification and source approval.

Definition of Alloy

An alloy is formed when two or more metallic materials are fused together.### Tungsten Carbide Bonding
Cobalt is the common bonding material for tungsten carbide used in cutting tools.

Grain Size and Mechanical Properties

Large grain size, resulting from slow cooling rates, results in lower tensile strength.
Materials with large grain size are more susceptible to creep.

Fatigue Failure

Fatigue failure refers to the cracking of structural components under repeated stress that is below the ultimate tensile load.

Duralumin Preparation

Duralumin must be solution treated, precipitation treated, and fitted to an aircraft within 2 hours, or alternatively just solution treated before fitting.

Aluminium Alloy Designation

The designation 2024-T4 indicates a copper-based aluminium alloy that is solution treated and naturally aged.

IADS Coding

A metal coded 1285 signifies it is 99.85% pure aluminium.

Monel Metal Composition

Monel metal is comprised of approximately 66% nickel and 33% copper.

Silver Solder Composition

Silver solder is made from copper, zinc, and silver.

Material Malleability vs. Ductility

Malleability refers to a material's ability to be forged, rolled, or extruded without fracture, while ductility indicates the ability to undergo plastic deformation without breaking.

Fatigue Definition

Fatigue is defined as the cyclic stressing of a part, which can lead to failure over time.

Stop Drilling Technique

Stop drilling is performed at the end of a crack to prevent its propagation.

Annealing of Aluminium

Annealing aluminium effectively removes stresses caused by forming processes.

Brinell Hardness Test

In the Brinell hardness test, the diameter of the indentation is measured to determine hardness.

Impact Testing

Impact testing is employed to assess a material's toughness, measuring its resistance to impact forces.

S-N Curve

The S-N curve is utilized to evaluate fatigue life, illustrating the relationship between stress levels (S) and the number of cycles to failure (N).

Fusible Materials

Fusible materials refer to metals with the ability to melt.

Brittleness Definition

Brittleness is characterized as the property of a material that does not deform before fracturing.

Proof Stress

Proof stress is defined as the stress level at which a small amount of permanent deformation, or set, occurs.

Young's Modulus

Young's Modulus is a measure of a material's stiffness, relating stress and strain in the elastic region.

Hooke's Law

Hooke's Law states that within the elastic limit, strain is directly proportional to stress.

SI Unit for Strain

Strain is a dimensionless quantity and does not have any units.

Calculating Stress

Stress can be calculated using the formula: Load / Cross-sectional area.

Yield Strength

A material's yield strength indicates its ability to resist deformation when subjected to stress.

Tensile Testing

Tensile testing involves stretching a material until it breaks to measure its strength properties.

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Description

Test your understanding of suitable chemical mixtures used in salt bath operations. This quiz covers the correct proportions and components necessary for effective mixing. Improve your knowledge of chemical applications in industrial processes.