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