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