材料物理导论 试卷及参考答案-试卷及参考答案-answer1 B

河北大学课程考核参考答案及评分标准

（—学年第学期）

考核科目材料物理导论课程类别考核方式开卷卷别 B

1. Differentiate the conceptions, point out the difference and sameness. (20 points, 5 points for each question)

1) Uphill diffusion and downhill diffusion

Difference: diffusion direction

Sameness: driving force -chemical potential gradient

2) Whole dislocation and no-whole dislocation

Difference: The relationship between Burgers vector and lattice constant is different.

Sameness: They are both line defect, that is, dislocations

3)Eutectic transformation and eutectoid transformation

Difference: Eutectic transformation is liquid phase transition, eutectoid transformation is solid phase transformation.

Sameness: transformation products are two solid phases in constant temperature.

4)Phase and organization

Difference: Organization has a particular morphology.

Sameness: They are the components of materials.

2. True or False. (20 points, 4 points for each question)

1) A Force acts on dislocation line, its direction is always perpendicular to dislocation line

and the direction points to no-slip area. (true) 2) When metal is crystallized, atoms are from disarrangement of the liquid to arrangement of solid phase. The entropy of system decreases, so it is a spontaneous process. (false)

3) In the two-phase region of the vertical sections of ternary phase diagram is not suitable

for lever rule. (true) 4) When plastic deformation occurs, the slip surface is always close-packed face of crystal

and the slip direction is always the close-packed direction. (ture)

5) Except Co element, all alloy elements which be integrated into the austenite can make

C curve to the left, therefore the hardenability of steel will increase. (false)

3. Plane B: (122). (10 points)

4. t is about 3000min. (25 points)

5. T=900K(627o C). (25 points)