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