Engineering Materials Flashcards: Plastics, Metals and Processing

このデッキのカード

1. カード 1

   質問

   Engineering stress in a tensile test: force divided by what?

   回答

   Original specimen cross-sectional area.

2. カード 2

   質問

   Engineering strain in a tensile test: extension divided by what?

   回答

   Original gauge length. Strain is dimensionless.

3. カード 3

   質問

   Elastic deformation: what happens after unloading?

   回答

   The deformation recovers.

4. カード 4

   質問

   Young’s modulus describes which material behaviour?

   回答

   Resistance to elastic tensile or compressive strain, in the linear elastic region.

5. カード 5

   質問

   Yield strength marks the onset of what?

   回答

   Significant permanent deformation, using the specified yield or proof criterion.

6. カード 6

   質問

   Ultimate tensile strength: which point on an engineering stress–strain curve?

   回答

   The maximum engineering tensile stress.

7. カード 7

   質問

   Ductility describes what happens before tensile fracture?

   回答

   How much plastic deformation the material can undergo.

8. カード 8

   質問

   Indentation hardness measures resistance to what?

   回答

   Localized permanent penetration by an indenter.

9. カード 9

   質問

   Tensile toughness: what does the area under the stress–strain curve to fracture represent?

   回答

   Energy absorbed per unit volume up to fracture under those test conditions.

10. カード 10

    質問

    Density relates which two quantities?

    回答

    Mass per unit volume.

11. カード 11

    質問

    Thermal conductivity describes which ability?

    回答

    Transferring heat through a material under a temperature gradient.

12. カード 12

    質問

    Electrical conductivity describes which ability?

    回答

    Carrying electric current under an electric field.

13. カード 13

    質問

    Creep: what changes under a sustained load over time?

    回答

    Deformation increases with time; temperature and stress affect the rate.

14. カード 14

    質問

    Fatigue damage is associated with what loading pattern?

    回答

    Repeated or fluctuating loading that can initiate and grow cracks.

15. カード 15

    質問

    Brittle fracture: how much plastic deformation precedes it?

    回答

    Little plastic deformation compared with ductile fracture under the same test conditions.

16. カード 16

    質問

    A bracket bends too far but recovers fully. Which property should you examine first?

    回答

    Elastic stiffness: material modulus together with the bracket’s geometry.

17. カード 17

    質問

    A metal clip stays bent after one overload. Which threshold was exceeded locally?

    回答

    Its yield threshold; permanent deformation occurred.

18. カード 18

    質問

    A housing must absorb a drop without fracture. Which evidence matters beyond tensile strength?

    回答

    Impact-test performance under relevant temperature, notch and geometry conditions.

19. カード 19

    質問

    Two materials have equal yield strength. Must their tensile toughness be equal?

    回答

    No. Different ductility can produce different energy absorption before fracture.

20. カード 20

    質問

    A plastic clamp slowly loosens at fixed deflection. Which time-dependent effect is this?

    回答

    Stress relaxation: the stress decreases while the imposed deformation is held.

21. カード 21

    質問

    Does a higher hardness alone prove a part will resist every wear mechanism?

    回答

    No. Wear also depends on contact, loading, lubrication and the wear mechanism.

22. カード 22

    質問

    Why compare impact results only with matching test conditions?

    回答

    Specimen geometry, notches, temperature and test method affect measured impact behaviour.

23. カード 23

    質問

    Can a generic family property range serve as a finished-part design allowable?

    回答

    No. Select a grade, condition and relevant design data before qualifying the part.

24. カード 24

    質問

    A lighter material is proposed for the same-size part. Which property predicts its mass change?

    回答

    Density, provided the volume remains the same.

25. カード 25

    質問

    Ferrous versus nonferrous metals: what is the defining distinction?

    回答

    Whether iron is the main constituent. Nonferrous does not mean completely iron-free.

26. カード 26

    質問

    Steel belongs to which basic alloy family?

    回答

    Iron-based alloys containing carbon, often with other alloying elements.

27. カード 27

    質問

    Why specify a steel grade and heat treatment rather than just “steel”?

    回答

    Composition and processing change its microstructure and mechanical properties.

28. カード 28

    質問

    What is a grain in a polycrystalline metal?

    回答

    A crystalline region with a particular lattice orientation.

29. カード 29

    質問

    What separates neighbouring metal grains with different orientations?

    回答

    A grain boundary.

30. カード 30

    質問

    Which crystal defect commonly moves during plastic deformation of metals?

    回答

    A dislocation.

31. カード 31

    質問

    Cold working usually trades increased strength for what?

    回答

    Reduced ductility, as plastic deformation impedes further dislocation motion.

32. カード 32

    質問

    What is a common purpose of annealing a cold-worked metal?

    回答

    Restore ductility and reduce hardness through a controlled heat treatment.

33. カード 33

    質問

    Quenching in metal heat treatment means what cooling step?

    回答

    Rapid cooling using a specified medium; the appropriate regime depends on the alloy and intended result.

34. カード 34

    質問

    What gives stainless steel much of its corrosion resistance?

    回答

    A thin chromium-rich passive surface film.

35. カード 35

    質問

    Why distinguish grey cast iron from ductile cast iron during selection?

    回答

    Graphite form and resulting mechanical behaviour differ; “cast iron” is not one property set.

36. カード 36

    質問

    Why are aluminium alloys often screened for lightweight structures?

    回答

    Their relatively low density can help reduce mass; stiffness, strength and geometry still need checking.

37. カード 37

    質問

    Why is copper often screened for electrical conductors?

    回答

    High electrical conductivity; cost, strength and connection design also matter.

38. カード 38

    質問

    Brass is principally an alloy of copper with which element?

    回答

    Zinc.

39. カード 39

    質問

    Traditional tin bronze is principally an alloy of which two elements?

    回答

    Copper and tin. Other bronze families use different alloying additions.

40. カード 40

    質問

    Does “stainless” mean immune to chloride corrosion?

    回答

    No. Grade, environment and surface condition still govern corrosion resistance.

41. カード 41

    質問

    Two dissimilar metals touch in salty water. Which corrosion mechanism should be checked?

    回答

    Galvanic corrosion, because electrical contact and an electrolyte can form a galvanic couple.

42. カード 42

    質問

    Can you rank aluminium and steel parts by stiffness using only their material names?

    回答

    No. Compare the actual moduli and part geometries for the required loading.

43. カード 43

    質問

    A copper alloy is stronger than pure copper. Must it conduct electricity equally well?

    回答

    No. Alloying changes conductivity as well as mechanical properties; check that alloy’s data.

44. カード 44

    質問

    A steel sheet cracks during forming after extensive cold work. What processing step may restore formability?

    回答

    An appropriate anneal before further forming; confirm the alloy-specific procedure.

45. カード 45

    質問

    What is a common purpose of tempering a quench-hardened steel?

    回答

    Improve toughness and ductility, usually with some reduction in hardness.

46. カード 46

    質問

    How can an insulating washer help a dissimilar-metal joint resist galvanic corrosion?

    回答

    By interrupting the electrical connection, if the whole joint is electrically isolated.

47. カード 47

    質問

    Before approving a welded metal component, which material region besides the weld metal needs consideration?

    回答

    The heat-affected zone, whose thermal cycle can change properties without melting it.

48. カード 48

    質問

    What is the key processing–structure–property lesson for metal selection?

    回答

    A chemical composition alone does not determine performance; processing changes microstructure.

49. カード 49

    質問

    A polymer is built from what kind of molecular structure?

    回答

    Large molecules containing many linked repeating units.

50. カード 50

    質問

    Which polymer class can usually be reheated and reshaped: thermoplastics or cured thermosets?

    回答

    Thermoplastics. Cross-links in a cured thermoset prevent ordinary melt reshaping.

51. カード 51

    質問

    What deformation behaviour distinguishes an elastomer?

    回答

    It can undergo substantial deformation and recover toward its original shape when the load is removed, within its working range.

52. カード 52

    質問

    What does “semi-crystalline polymer” mean?

    回答

    Ordered crystalline regions coexist with amorphous regions.

53. カード 53

    質問

    Which polymer regions undergo glass transition: amorphous or crystalline?

    回答

    Amorphous regions. Around the glass transition, motion of chain segments becomes much easier.

54. カード 54

    質問

    What structural feature prevents a cured thermoset from flowing like a thermoplastic melt?

    回答

    A covalently cross-linked network.

55. カード 55

    質問

    Why are plasticizers added to some polymer formulations?

    回答

    To increase flexibility; the amount and compatibility affect the final properties.

56. カード 56

    質問

    Why add UV stabilizers to a polymer intended for outdoor exposure?

    回答

    To reduce degradation caused by ultraviolet exposure; the formulation and exposure still need verification.

57. カード 57

    質問

    Why can adding glass fibres make moulded polymer properties direction-dependent?

    回答

    Fibres become oriented during flow, so reinforcement differs with direction.

58. カード 58

    質問

    What structural change separates glass transition from crystalline melting in a polymer?

    回答

    Glass transition increases chain-segment mobility in amorphous regions; melting breaks down the ordered crystalline regions.

59. カード 59

    質問

    ABS is an abbreviation for which polymer name?

    回答

    Acrylonitrile butadiene styrene.

60. カード 60

    質問

    PA6 is another name for which polyamide?

    回答

    Polyamide 6, also called nylon 6.

61. カード 61

    質問

    Why distinguish “dry” from “conditioned” polyamide property data?

    回答

    Moisture conditioning changes the material state and can change mechanical behaviour.

62. カード 62

    質問

    Does one grade’s ABS datasheet establish the properties of every ABS grade?

    回答

    No. Formulation, grade, test method and conditions must match the claim.

63. カード 63

    質問

    INEOS Terluran GP-22 is specified for which main shaping process?

    回答

    Injection moulding; it is a general-purpose ABS grade.

64. カード 64

    質問

    BASF Ultramid B3S is supplied for which main shaping process?

    回答

    Injection moulding; BASF describes this PA6 grade as easy-flowing and finely crystalline.

65. カード 65

    質問

    A warm polymer bracket carries a constant load for months. Which data are needed beyond a short tensile test?

    回答

    Long-term creep data for the relevant load, temperature and material condition.

66. カード 66

    質問

    Ultramid B3EG6 differs from unreinforced PA6 by which reinforcement?

    回答

    BASF specifies glass-fibre reinforcement for this PA6 injection-moulding grade.

67. カード 67

    質問

    Which part category does INEOS identify as a particular application for Terluran GP-22?

    回答

    Housings, including appliance housings. This is a candidate application, not automatic design approval.

68. カード 68

    質問

    Why keep opened Ultramid B3S granule containers carefully closed?

    回答

    To limit moisture absorption before processing.

69. カード 69

    質問

    Can glass-filled PA6 data replace unfilled PA6 data in a design check?

    回答

    No. Reinforcement changes the material; use the exact grade and relevant orientation data.

70. カード 70

    質問

    Must a thermoplastic part be accepted by the local recycling system?

    回答

    No. Remeltability alone does not establish collection, sorting or recycling compatibility.

71. カード 71

    質問

    For an outdoor ABS housing, is a good indoor impact result enough evidence?

    回答

    No. Check weathering, temperature and the exact grade’s suitability for the exposure.

72. カード 72

    質問

    BASF lists grips and fixing clamps for Ultramid B3S. What remains to verify for a loaded clamp?

    回答

    Grade-specific long-term behaviour at the actual temperature and moisture state, plus the part geometry.

73. カード 73

    質問

    Metal casting shapes a part by which change of state?

    回答

    Liquid metal solidifies inside a mould.

74. カード 74

    質問

    Forging shapes metal by what basic mechanism?

    回答

    Compressive plastic deformation of solid metal; it may be performed hot or cold.

75. カード 75

    質問

    Extrusion is particularly suited to which basic geometry?

    回答

    A continuous length with a substantially constant cross-section, formed through a die.

76. カード 76

    質問

    CNC machining is additive or subtractive?

    回答

    Subtractive: controlled cutting removes material from a workpiece.

77. カード 77

    質問

    Injection moulding of a thermoplastic: what happens after the cavity fills?

    回答

    The melt cools and solidifies before the part is ejected.

78. カード 78

    質問

    Thermoforming starts from which form of plastic stock?

    回答

    A sheet heated until formable, then shaped over or into a mould.

79. カード 79

    質問

    Blow moulding is commonly used for which type of plastic part?

    回答

    Hollow parts, such as bottles, formed by inflating a heated preform or tube in a mould.

80. カード 80

    質問

    Additive manufacturing builds geometry by what basic approach?

    回答

    Adding material, commonly layer by layer, from a digital model.

81. カード 81

    質問

    In milling, what typically rotates to remove material?

    回答

    The cutting tool.

82. カード 82

    質問

    Why may a cast part still need machining?

    回答

    Selected surfaces may need tighter tolerances or a better finish than the casting provides.

83. カード 83

    質問

    Sand casting and permanent-mould casting mainly differ in what tooling feature?

    回答

    Sand moulds are expendable; permanent moulds are reused.

84. カード 84

    質問

    Why can injection moulding be costly for a very small production run?

    回答

    Tooling cost is spread across too few parts; compare total cost at the required volume.

85. カード 85

    質問

    A long plastic tube has the same cross-section throughout. Which process is a natural first candidate?

    回答

    Extrusion, followed by cooling and cutting to length.

86. カード 86

    質問

    A thin plastic packaging tray must be formed from sheet. Which process is a natural first candidate?

    回答

    Thermoforming; check wall thinning and the required detail.

87. カード 87

    質問

    Why should a forged part’s grain flow be considered in design?

    回答

    Deformation creates directional structure; the load direction and process route affect performance.

88. カード 88

    質問

    A design needs a few changing metal prototypes. Why consider CNC machining before buying a production mould?

    回答

    It can make revised parts directly from stock without dedicated mould tooling.

89. カード 89

    質問

    What distinguishes a fusion-weld heat-affected zone from the fusion zone?

    回答

    The heat-affected zone changes thermally but does not melt; the fusion zone melts and resolidifies.

90. カード 90

    質問

    Why clean and prepare a metal surface before applying a protective coating?

    回答

    Contaminants and surface defects can impair coating adhesion and performance.

91. カード 91

    質問

    Does a corrosion-resistant coating make the underlying material irrelevant?

    回答

    No. Damage, adhesion, exposure and substrate compatibility still matter.

92. カード 92

    質問

    Why check build orientation when selecting a layer-built polymer part?

    回答

    Layer bonding and deposition can make strength depend on direction.

93. カード 93

    質問

    A hollow plastic bottle needs a shaped enclosed body. Which process family should you screen first?

    回答

    Blow moulding; select the exact variant for the material and geometry.

94. カード 94

    質問

    Many identical thermoplastic housings are needed. Which process deserves early cost comparison?

    回答

    Injection moulding, because repeat production can spread tooling cost over many parts.

95. カード 95

    質問

    Why does choosing a process also affect material selection?

    回答

    Materials must tolerate that process and achieve the required finished-part properties.

96. カード 96

    質問

    Before releasing a selected material–process combination, what evidence closes the selection loop?

    回答

    Verify the exact grade, processing condition and part performance against the actual requirements.

96枚のカード

Engineering Materials Flashcards: Plastics, Metals and Processing

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