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