大学MOOC Engineering Materials(Chang'an University)1458243165 最新慕课完整章节测试答案
1 Mechanical Properties of Engineering Materials
文章目录
Mechanical Properties of Engineering Materials
1、单选题：
In the following hardness measurement method, the diamond head is used for ( ).
选项：
A: HV
B: HRC
C: HB
D: HRA
答案: 【 HV】
2、单选题：
The following statement about fatigue is true ( ).
选项：
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、单选题：
What's true about the fracture is that ( ).
选项：
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、单选题：
KIC is the index of fracture toughness of type I crack. The following statement is correct ( ).
选项：
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、单选题：
Improving lubrication conditions and enhancing the stability of the oxide film are targeted at that type of wear ( ).
选项：
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、单选题：
The number of atoms contained in a dense cubic cell is ( ).
选项：
A: 2
B: 3
C: 6
D: 8
答案: 【 6】
2、单选题：
In the crystals of the following substances, the substance with ionic bonds is ( ).
选项：
A: SO2
B: SiO2
C: NaCl
D: H2O
答案: 【 NaCl】
3、单选题：
( ) are the most basic and independent components in the alloy.
选项：
A: component
B: alloy
C: phase
D: solid solution
答案: 【 component】
4、单选题：
Among the following defects, ( ) belongs to the point defect.
选项：
A: positive edge dislocation
B: Frenkel defect
C: negative edge dislocation
D: screw dislocation
答案: 【 Frenkel defect】
5、单选题：
In the following objects, ( ) belongs to crystal.
选项：
A: ice
B: glass
C: rosin
D: asphalt
答案: 【 ice】