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