Engineering Materials Flashcards: Plastics, Metals and Processing
96 English cards on material properties, metal and polymer families, manufacturing processes, and qualified selection cases, including sourced ABS and PA6 grades.
About this deck
Learn engineering materials through concise retrieval and constrained selection problems. These 96 original English cards connect property vocabulary, metal and polymer families, processing mechanisms and practical evidence checks.
Practise concept-to-explanation recall, selected situation-to-property or process choices, alloy-family recognition, and named-grade interpretation for ABS (INEOS Terluran GP-22) and PA6 (BASF Ultramid B3S and B3EG6). A suggested material or process is a screening candidate, not a qualified design.
The sequence introduces properties, then metals, polymers and manufacturing processes. Each topic progresses from mechanisms to applications. Selected case variants are separated from their foundation cards; the review scheduler handles later spacing.
Excluded: automatic reverse cards for every definition, generic numerical property rankings, machine settings, full phase diagrams and design allowables. Exact material properties require the correct grade, test method, temperature, moisture state, orientation and processing history. This is an evergreen topic deck, not a complete materials course or exam syllabus.
AI-assisted questions, answers and generated cover were independently composed and checked against technical sources. No private learner cards, textbook exercises, exam questions or third-party images were copied. Original wording, organization and generated media are offered under CC0 1.0 to the extent applicable rights exist; facts and third-party source material retain their own status.
Factual references include INEOS Terluran GP-22, BASF Ultramid, University of Illinois materials principles, Instron materials testing terms, TWI injection moulding and American Foundry Society metalcasting.
Independent educational material; no affiliation with or endorsement by the named manufacturers, technical bodies or universities.
Cards in this deck
Card 1
Question
Engineering stress in a tensile test: force divided by what?
Answer
Original specimen cross-sectional area.
Card 2
Question
Engineering strain in a tensile test: extension divided by what?
Answer
Original gauge length. Strain is dimensionless.
Card 3
Question
Elastic deformation: what happens after unloading?
Answer
The deformation recovers.
Card 4
Question
Young’s modulus describes which material behaviour?
Answer
Resistance to elastic tensile or compressive strain, in the linear elastic region.
Card 5
Question
Yield strength marks the onset of what?
Answer
Significant permanent deformation, using the specified yield or proof criterion.
Card 6
Question
Ultimate tensile strength: which point on an engineering stress–strain curve?
Answer
The maximum engineering tensile stress.
Card 7
Question
Ductility describes what happens before tensile fracture?
Answer
How much plastic deformation the material can undergo.
Card 8
Question
Indentation hardness measures resistance to what?
Answer
Localized permanent penetration by an indenter.
Card 9
Question
Tensile toughness: what does the area under the stress–strain curve to fracture represent?
Answer
Energy absorbed per unit volume up to fracture under those test conditions.
Card 10
Question
Density relates which two quantities?
Answer
Mass per unit volume.
Card 11
Question
Thermal conductivity describes which ability?
Answer
Transferring heat through a material under a temperature gradient.
Card 12
Question
Electrical conductivity describes which ability?
Answer
Carrying electric current under an electric field.
Card 13
Question
Creep: what changes under a sustained load over time?
Answer
Deformation increases with time; temperature and stress affect the rate.
Card 14
Question
Fatigue damage is associated with what loading pattern?
Answer
Repeated or fluctuating loading that can initiate and grow cracks.
Card 15
Question
Brittle fracture: how much plastic deformation precedes it?
Answer
Little plastic deformation compared with ductile fracture under the same test conditions.
Card 16
Question
A bracket bends too far but recovers fully. Which property should you examine first?
Answer
Elastic stiffness: material modulus together with the bracket’s geometry.
Card 17
Question
A metal clip stays bent after one overload. Which threshold was exceeded locally?
Answer
Its yield threshold; permanent deformation occurred.
Card 18
Question
A housing must absorb a drop without fracture. Which evidence matters beyond tensile strength?
Answer
Impact-test performance under relevant temperature, notch and geometry conditions.
Card 19
Question
Two materials have equal yield strength. Must their tensile toughness be equal?
Answer
No. Different ductility can produce different energy absorption before fracture.
Card 20
Question
A plastic clamp slowly loosens at fixed deflection. Which time-dependent effect is this?
Answer
Stress relaxation: the stress decreases while the imposed deformation is held.
Card 21
Question
Does a higher hardness alone prove a part will resist every wear mechanism?
Answer
No. Wear also depends on contact, loading, lubrication and the wear mechanism.
Card 22
Question
Why compare impact results only with matching test conditions?
Answer
Specimen geometry, notches, temperature and test method affect measured impact behaviour.
Card 23
Question
Can a generic family property range serve as a finished-part design allowable?
Answer
No. Select a grade, condition and relevant design data before qualifying the part.
Card 24
Question
A lighter material is proposed for the same-size part. Which property predicts its mass change?
Answer
Density, provided the volume remains the same.
Card 25
Question
Ferrous versus nonferrous metals: what is the defining distinction?
Answer
Whether iron is the main constituent. Nonferrous does not mean completely iron-free.
Card 26
Question
Steel belongs to which basic alloy family?
Answer
Iron-based alloys containing carbon, often with other alloying elements.
Card 27
Question
Why specify a steel grade and heat treatment rather than just “steel”?
Answer
Composition and processing change its microstructure and mechanical properties.
Card 28
Question
What is a grain in a polycrystalline metal?
Answer
A crystalline region with a particular lattice orientation.
Card 29
Question
What separates neighbouring metal grains with different orientations?
Answer
A grain boundary.
Card 30
Question
Which crystal defect commonly moves during plastic deformation of metals?
Answer
A dislocation.
Card 31
Question
Cold working usually trades increased strength for what?
Answer
Reduced ductility, as plastic deformation impedes further dislocation motion.
Card 32
Question
What is a common purpose of annealing a cold-worked metal?
Answer
Restore ductility and reduce hardness through a controlled heat treatment.
Card 33
Question
Quenching in metal heat treatment means what cooling step?
Answer
Rapid cooling using a specified medium; the appropriate regime depends on the alloy and intended result.
Card 34
Question
What gives stainless steel much of its corrosion resistance?
Answer
A thin chromium-rich passive surface film.
Card 35
Question
Why distinguish grey cast iron from ductile cast iron during selection?
Answer
Graphite form and resulting mechanical behaviour differ; “cast iron” is not one property set.
Card 36
Question
Why are aluminium alloys often screened for lightweight structures?
Answer
Their relatively low density can help reduce mass; stiffness, strength and geometry still need checking.
Card 37
Question
Why is copper often screened for electrical conductors?
Answer
High electrical conductivity; cost, strength and connection design also matter.
Card 38
Question
Brass is principally an alloy of copper with which element?
Answer
Zinc.
Card 39
Question
Traditional tin bronze is principally an alloy of which two elements?
Answer
Copper and tin. Other bronze families use different alloying additions.
Card 40
Question
Does “stainless” mean immune to chloride corrosion?
Answer
No. Grade, environment and surface condition still govern corrosion resistance.
Card 41
Question
Two dissimilar metals touch in salty water. Which corrosion mechanism should be checked?
Answer
Galvanic corrosion, because electrical contact and an electrolyte can form a galvanic couple.
Card 42
Question
Can you rank aluminium and steel parts by stiffness using only their material names?
Answer
No. Compare the actual moduli and part geometries for the required loading.
Card 43
Question
A copper alloy is stronger than pure copper. Must it conduct electricity equally well?
Answer
No. Alloying changes conductivity as well as mechanical properties; check that alloy’s data.
Card 44
Question
A steel sheet cracks during forming after extensive cold work. What processing step may restore formability?
Answer
An appropriate anneal before further forming; confirm the alloy-specific procedure.
Card 45
Question
What is a common purpose of tempering a quench-hardened steel?
Answer
Improve toughness and ductility, usually with some reduction in hardness.
Card 46
Question
How can an insulating washer help a dissimilar-metal joint resist galvanic corrosion?
Answer
By interrupting the electrical connection, if the whole joint is electrically isolated.
Card 47
Question
Before approving a welded metal component, which material region besides the weld metal needs consideration?
Answer
The heat-affected zone, whose thermal cycle can change properties without melting it.
Card 48
Question
What is the key processing–structure–property lesson for metal selection?
Answer
A chemical composition alone does not determine performance; processing changes microstructure.
Card 49
Question
A polymer is built from what kind of molecular structure?
Answer
Large molecules containing many linked repeating units.
Card 50
Question
Which polymer class can usually be reheated and reshaped: thermoplastics or cured thermosets?
Answer
Thermoplastics. Cross-links in a cured thermoset prevent ordinary melt reshaping.
Card 51
Question
What deformation behaviour distinguishes an elastomer?
Answer
It can undergo substantial deformation and recover toward its original shape when the load is removed, within its working range.
Card 52
Question
What does “semi-crystalline polymer” mean?
Answer
Ordered crystalline regions coexist with amorphous regions.
Card 53
Question
Which polymer regions undergo glass transition: amorphous or crystalline?
Answer
Amorphous regions. Around the glass transition, motion of chain segments becomes much easier.
Card 54
Question
What structural feature prevents a cured thermoset from flowing like a thermoplastic melt?
Answer
A covalently cross-linked network.
Card 55
Question
Why are plasticizers added to some polymer formulations?
Answer
To increase flexibility; the amount and compatibility affect the final properties.
Card 56
Question
Why add UV stabilizers to a polymer intended for outdoor exposure?
Answer
To reduce degradation caused by ultraviolet exposure; the formulation and exposure still need verification.
Card 57
Question
Why can adding glass fibres make moulded polymer properties direction-dependent?
Answer
Fibres become oriented during flow, so reinforcement differs with direction.
Card 58
Question
What structural change separates glass transition from crystalline melting in a polymer?
Answer
Glass transition increases chain-segment mobility in amorphous regions; melting breaks down the ordered crystalline regions.
Card 59
Question
ABS is an abbreviation for which polymer name?
Answer
Acrylonitrile butadiene styrene.
Card 60
Question
PA6 is another name for which polyamide?
Answer
Polyamide 6, also called nylon 6.
Card 61
Question
Why distinguish “dry” from “conditioned” polyamide property data?
Answer
Moisture conditioning changes the material state and can change mechanical behaviour.
Card 62
Question
Does one grade’s ABS datasheet establish the properties of every ABS grade?
Answer
No. Formulation, grade, test method and conditions must match the claim.
Card 63
Question
INEOS Terluran GP-22 is specified for which main shaping process?
Answer
Injection moulding; it is a general-purpose ABS grade.
Card 64
Question
BASF Ultramid B3S is supplied for which main shaping process?
Answer
Injection moulding; BASF describes this PA6 grade as easy-flowing and finely crystalline.
Card 65
Question
A warm polymer bracket carries a constant load for months. Which data are needed beyond a short tensile test?
Answer
Long-term creep data for the relevant load, temperature and material condition.
Card 66
Question
Ultramid B3EG6 differs from unreinforced PA6 by which reinforcement?
Answer
BASF specifies glass-fibre reinforcement for this PA6 injection-moulding grade.
Card 67
Question
Which part category does INEOS identify as a particular application for Terluran GP-22?
Answer
Housings, including appliance housings. This is a candidate application, not automatic design approval.
Card 68
Question
Why keep opened Ultramid B3S granule containers carefully closed?
Answer
To limit moisture absorption before processing.
Card 69
Question
Can glass-filled PA6 data replace unfilled PA6 data in a design check?
Answer
No. Reinforcement changes the material; use the exact grade and relevant orientation data.
Card 70
Question
Must a thermoplastic part be accepted by the local recycling system?
Answer
No. Remeltability alone does not establish collection, sorting or recycling compatibility.
Card 71
Question
For an outdoor ABS housing, is a good indoor impact result enough evidence?
Answer
No. Check weathering, temperature and the exact grade’s suitability for the exposure.
Card 72
Question
BASF lists grips and fixing clamps for Ultramid B3S. What remains to verify for a loaded clamp?
Answer
Grade-specific long-term behaviour at the actual temperature and moisture state, plus the part geometry.
Card 73
Question
Metal casting shapes a part by which change of state?
Answer
Liquid metal solidifies inside a mould.
Card 74
Question
Forging shapes metal by what basic mechanism?
Answer
Compressive plastic deformation of solid metal; it may be performed hot or cold.
Card 75
Question
Extrusion is particularly suited to which basic geometry?
Answer
A continuous length with a substantially constant cross-section, formed through a die.
Card 76
Question
CNC machining is additive or subtractive?
Answer
Subtractive: controlled cutting removes material from a workpiece.
Card 77
Question
Injection moulding of a thermoplastic: what happens after the cavity fills?
Answer
The melt cools and solidifies before the part is ejected.
Card 78
Question
Thermoforming starts from which form of plastic stock?
Answer
A sheet heated until formable, then shaped over or into a mould.
Card 79
Question
Blow moulding is commonly used for which type of plastic part?
Answer
Hollow parts, such as bottles, formed by inflating a heated preform or tube in a mould.
Card 80
Question
Additive manufacturing builds geometry by what basic approach?
Answer
Adding material, commonly layer by layer, from a digital model.
Card 81
Question
In milling, what typically rotates to remove material?
Answer
The cutting tool.
Card 82
Question
Why may a cast part still need machining?
Answer
Selected surfaces may need tighter tolerances or a better finish than the casting provides.
Card 83
Question
Sand casting and permanent-mould casting mainly differ in what tooling feature?
Answer
Sand moulds are expendable; permanent moulds are reused.
Card 84
Question
Why can injection moulding be costly for a very small production run?
Answer
Tooling cost is spread across too few parts; compare total cost at the required volume.
Card 85
Question
A long plastic tube has the same cross-section throughout. Which process is a natural first candidate?
Answer
Extrusion, followed by cooling and cutting to length.
Card 86
Question
A thin plastic packaging tray must be formed from sheet. Which process is a natural first candidate?
Answer
Thermoforming; check wall thinning and the required detail.
Card 87
Question
Why should a forged part’s grain flow be considered in design?
Answer
Deformation creates directional structure; the load direction and process route affect performance.
Card 88
Question
A design needs a few changing metal prototypes. Why consider CNC machining before buying a production mould?
Answer
It can make revised parts directly from stock without dedicated mould tooling.
Card 89
Question
What distinguishes a fusion-weld heat-affected zone from the fusion zone?
Answer
The heat-affected zone changes thermally but does not melt; the fusion zone melts and resolidifies.
Card 90
Question
Why clean and prepare a metal surface before applying a protective coating?
Answer
Contaminants and surface defects can impair coating adhesion and performance.
Card 91
Question
Does a corrosion-resistant coating make the underlying material irrelevant?
Answer
No. Damage, adhesion, exposure and substrate compatibility still matter.
Card 92
Question
Why check build orientation when selecting a layer-built polymer part?
Answer
Layer bonding and deposition can make strength depend on direction.
Card 93
Question
A hollow plastic bottle needs a shaped enclosed body. Which process family should you screen first?
Answer
Blow moulding; select the exact variant for the material and geometry.
Card 94
Question
Many identical thermoplastic housings are needed. Which process deserves early cost comparison?
Answer
Injection moulding, because repeat production can spread tooling cost over many parts.
Card 95
Question
Why does choosing a process also affect material selection?
Answer
Materials must tolerate that process and achieve the required finished-part properties.
Card 96
Question
Before releasing a selected material–process combination, what evidence closes the selection loop?
Answer
Verify the exact grade, processing condition and part performance against the actual requirements.
96 cards
Engineering Materials Flashcards: Plastics, Metals and Processing
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