材料科学基础_13.ppt

文档介绍：材料科学基础Fundamental of Materials
Prof: Tian Min Bo
Tel: [phone]
E-mail: ******@.
Department of Material Science and Engineering
Tsinghua University. Beijing 100084
Lesson thirteen
3. Application of Schmid’s law
How to determine the active . for all the equivalent .
Determine the active . by Reflection Rule.
Orientation cell for cubic crystals.
Given: BCC Crystal having {110}<111>slip system.
Determine : active slip system in response to tensile
loading along
Solution:
Draw a orientation cell.
Label the loading direction in the cell.
Determine the active . by reflection rule.
Determine the active slip systems by Schmidt's law
Draw a standard projection
x=z line
x=y line
y=z line
Label the loading direction in standard projection.
Mirror rule
case1.
along
FCC, orientation triangle :
slip system is
case2.
along
orientation triangle:
according to the mirror-refraction rule the active slip system is
given [u v w], determine active slip system
Determine the active slip systems by Reflection Rule.
Example:
Given: BCC crystal having {110}<111> slip system
Determine active slip system in response to tensile loading along .
Solve:
① Draw a standard projection.
② Label the loading direction in
standard projection.
③ Determine the active by
Reflection Rule.
④
locate inside the orientation triangle ( ), single slip.
locate at the edge of the orientation triangle ( ), double (duplex) slip.
locate at the corner of the orientation triangle, multiple slip.
When the axis of load is in the edge or corner of the orientation triangle, muli-slip occurs.
F1
F2
F3
A tensile force is applied on a BCC cylindrical bar with across section of 25mm2. The initial axis is . The CRSS is . The slip plane is .
Determine:
initial .
P
duplex .
the shear strain and the indices of the axis at the moment when duplex starts
stable position