粗晶LY-12合金准超塑性单轴拉伸模拟  

SIMULATION OF COARSE-GRAINED LY-12 QUASI-SUPERPLASTIC UNIAXIAL TENSION

作　　者：吴艳青[1] 张克实[1] 

机构地区：[1]西北工业大学工程力学系,西安710072

出　　处：《固体力学学报》2003年第3期313-320,共8页Chinese Journal of Solid Mechanics

基　　金：自然科学基金 ( 19972 0 55)资助 .

摘　　要：在试验的基础上 ,利用Chaboche本构模型对LY 1 2准超塑性单轴拉伸变形进行数值模拟 ,对其能够实现大延伸率的力学现象进行分析 .由于材料具有高应变速率敏感指数 ,颈缩不发生在标距中间 ,而是有多处出现颈缩 .不同颈缩相互的松弛作用对变形起重要作用 .模拟和试验都表明 ,温度一定 ,不同应变速率下 ,颈缩发生的位置和颈缩程度不同 ,从而最大破坏延伸率也不同 .利用该模型可以预测粗晶LY 1Based on test results, numerical simulation of quasi-superplastic uniaxial tension of LY-12 is implemented using Chaboche vis coplastic co nstitutive equations. Due to higher strain rate sensitivity to stress, we find t hat necks do not locate in the middle of the gauge length, and multiple necks ta k e place. Relaxation action between necks plays an important role to quasi-super plastic deformation. Both results of simulation and experiments show that the necked position a nd the neck extent are different under different strain rate at constant tempera ture, leading to different corresponding elongations to fracture. The model deve loped can be successfully used in predicting the coarse-grained LY-12 superpla stic deforming ability and the possible fracture position.\;

关 键 词：粗晶 LY-12合金 准超塑性 单轴拉伸 数值模拟 力学性能 材料试验 Chaboche本构模型 变形 

分 类 号：TG115.5[金属学及工艺—物理冶金]