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