FCC多晶体的黄铜型织构演化模拟

Simulation of Brass-type Texture Evolution of FCC Polycrystals

高层错能 FCC材料塑性变形主要靠晶体滑移 ,而对于低层错能材料 ,除晶体滑移之外 ,在维持正常塑性流动方面 ,变形孪晶也起重要作用。建立了可解释滑移和孪晶导致塑性变形的率相关本构模型 ,并在研究开发的有限元程序中予以实现 ,通过弹性 /晶体粘塑性分析计算 ,对面心立方金属在滑移与孪晶作用下的织构演化过程进行了计算机模拟。计算表明 ,在平面应变压缩下 ,黄铜晶体织构的演化是滑移和孪晶导致的晶格转动的结果 ,孪晶是造成低层错能

The face-centered cubic (f.c.c.) crystals with high stacking fault energies deform predominantly by crystallographic slip. For the crystals with low stacking fault energies, in addition to crystallographic slip, deformation twinning also plays an important role in maintaining generalized plastic flow. In this paper a rate-dependent constitutive model which accounts for both slip and twinning is established, and implemented by finite element computational procedures developed. The texture evolution of f.c.c. metals by slip and twinning was studied by using elastic/crystalline viscoplastic analysis. Simulation results show that in plane strain compression, the development of brass-type texture is a result of lattice rotation due to both slip and twinning, twinning is very important to the evolution of brass-type texture in f.c.c. metals with low stacking fault energies.