文档介绍：第七章固体材料的塑性变形
Chapter 7 Plastic Deformation
作业1:Identify the dislocation, in terms of its Burgers vector (Using vector notation) that can cross slip between the (111) and plane of an fcc crystal.
Solution:
作业2:There are three slip systems on an fcc octahedral plane. Assume a 2 MPa tensile stress is applied along the [100] direction of a gold crystal, whose critical resolred shear stress is . Demonstrate quantitatively that measurable slip will not occur on any of the three slip systems in the (111) plane as a result of this applied stress.
Solution:
The three slip systems in the (111) plane are (111) , (111) , (111) . Because [100], that is λ=, so ( resolred shear stress in (111)) is 0.
Another two
So:Measurable slip will not occur on any of the three slip systems in the (111) plane.
作业3.:An FCC crystal yields under a normal stress of 2 MPa applied in the [23] direction. The slip plane is (111) and the slip direction is [01]. Determine τcr for this crystal. (10 points)
Solution:
To solve this problem, we must find both cosθ and cosφ. This can be done suing the vector dot product:
Cosθ=
Cosφ=
Solving equation for τcR and substituting the data given in the problem statement yields:
τcR=(2Mpa)×()×()=
作业4:假定某面心立方晶体可以开动的滑移系为[011]。试回答:
(1)给出引起滑移的单位位错得相反矢量,并说明之。
(2)如果滑移是由纯刃位错引起的,试指出位错线的方向。
(3)指出上述情况下,滑移时位错线的运动方向。
(4)假定在该滑移系上作用一大小