凸苫懈箱班井输吾冀苍螺跑停
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起止时间:2021-03-08到2021-05-31
更新状态:已完结
1 Mechanical Properties of Engineering Materials Mechanical Properties of Engineering Materials
1、 In the following hardness measurement method, the diamond head is used for ( ).
A:HV
B:HRC
C:HB
D:HRA
答案: HV
2、 The following statement about fatigue is true ( ).
A:The stress of fatigue is higher than the yield strength of static load.
B:Obvious plastic deformation can be observed at fatigue fracture.
C:Fatigue fracture can be divided into fatigue source, bright area, rough area.
D:The occurrence of fatigue fracture is premonitory and is called brittle fracture.
答案: Fatigue fracture can be divided into fatigue source, bright area, rough area.
3、 What’s true about the fracture is that ( ).
A:Brittle material fracture fibrous.
B:Ductile materials have no obvious plastic deformation before fracture.
C:The fracture of the ductile material is crystalline and shiny.
D:The fracture of brittle materials is crystalline or porcelain.
答案: The fracture of brittle materials is crystalline or porcelain.
4、 KIC is the index of fracture toughness of type I crack. The following statement is correct ( ).
A:when KⅠ < KⅠC, crack began to expand, brittle fracture.
B:when KⅠ > KⅠC, crack extension occurs brittle fracture of instability.
C:when KⅠ = KⅠC, extension began to occur.
D:when KⅠ = 1/2KⅠC, crack extension.
答案: when KⅠ > KⅠC, crack extension occurs brittle fracture of instability.
5、 Improving lubrication conditions and enhancing the stability of the oxide film are targeted at that type of wear ( ).
A:abrasive wear
B:contact fatigue wear
C:adhesive wear
D:corrosion and wear
答案: adhesive wear
2 Microstructure of Engineering Materials Microstructure of Engineering Materials
1、 The number of atoms contained in a dense cubic cell is ( ).
A:2
B:3
C:6
D:8
答案: 6
2、 In the crystals of the following substances, the substance with ionic bonds is ( ).
A:SO2
B:SiO2
C:NaCl
D:H2O
答案: NaCl
3、 ( ) are the most basic and independent components in the alloy.
A:component
B:alloy
C:phase
D:solid solution
答案: component
4、 Among the following defects, ( ) belongs to the point defect.
A:positive edge dislocation
B:Frenkel defect
C:negative edge dislocation
D:screw dislocation
答案: Frenkel defect
5、 In the following objects, ( ) belongs to crystal.
A:ice
B:glass
C:rosin
D:asphalt
答案: ice
3 Solidification and Crystallization of Engineering Materials Solidification and Crystallization of
1、 For a given alloy at a certain temperature, the composition of the two equilibrium phases only needs to be a parallel line of the abscissa of the composition at that ( ). The intersection of the parallel line and the curves in the phase diagram corresponds to the composition of the two equilibrium phases.
A:Temperature
B:Quality
C:Quality score
D:Molar mass
答案: Temperature
2、 Generally, when the solid solution is crystallized in equilibrium, the composition of the liquid phase changes along the ( ) line and the composition of the solid phase changes along the solidus line, and finally a solid solution with uniform composition is obtained.
A:Solid phase
B:Liquidus
C:Solid-liquid interface
D:Above the liquid surface
答案: Liquidus
3、 Taking the binary phase diagram of Pb-Sn alloy as an example, there are ( ) single phase regions.
A:Two
B:Three
C:Four
D:Five
答案: Three
4、 Peritectic phase diagram: two groups of elements can ( ) in liquid state , but in the solid state, it can only be dissolved in a limited amount and has a phase diagram of peritectic transition.
A:Infinite dissolution
B:Limited dissolution
C:Dissolve with each other
D:Dissolve half
答案: Infinite dissolution
5、 The alloy phase diagram is an important diagram reflecting the equilibrium crystallization characteristics of the alloy, as well as the relationship between the alloy composition and the balance structure, and the performance of the alloy mainly depends on the composition and structure of the alloy, so the performance of the alloy can be qualitatively judged according to the ( ).
A:Composition of alloy
B:Structure of alloy
C:Phase diagrams
D:Composition and structure of alloy
答案: Phase diagrams
4 Plastic Deformation and Recrystallization of Metals Plastic Deformation and Recrystallization of M
1、 When a solid is subjected to external force, it will ( ) .
A:change in shape
B:change in property
C:slide
D:occur plastic deformation
答案: change in shape
2、 The plastic deformation of polycrystal is much more complicated than that of monocrystal mainly because of ( ) .
A:impurity atoms
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