摘要
气炮加载和冲击波测量技术用于研究了Ｔａ－Ｗ合金在平板撞击条件下的动态断裂过程。在应变率为１０４Ｓ－１～１０５Ｓ－１范围内，平板撞击加载使Ｔａ－Ｗ合金靶产生两种典型的动态断裂—层裂断口。在中等入射应力下，即入射应力强度稍高于靶的层裂强度时，由晶粒边界形成孔洞并连接成微裂纹，裂纹沿晶界扩展导致靶样沿晶界刻面断裂的层裂断口；在较高入射应力下，靶样的塑性变形，不仅在晶界产生裂纹，而且在晶粒内部的各种缺陷位置也萌生解理裂纹，孪生塑变产生的形变孪晶促进了解理裂纹的萌生和发展；当入射应力达到或超过解理裂纹扩展所需应力时，靶样将出现典型的穿晶解理层裂。合金中的组织缺陷对动态断裂的影响和不同入射应力下合金靶的动态断裂类型的变化机制也进行了讨论。
The dynamic fracture modes of a Ta-W alloy under planar impact has been investigated using a gas gun and shock wave measurement.There are two typical dynamic fracture modes in Ta-W alloy targets under strain rates of the order of 104s-1～105s-1produced by gas-gun activated plate impacts. At a middle stress levels,i.e.the strength of incident stress wave is only slightly greater than the spall strength of the target,the tensile voids at grain boundaries in the target will eventually join up to form cracks,the cracks then propagate along grain boundaries to form an intergranular spall fracture surface. At high stress levels,not only the intergranular cracks but also the cleavage cracks will form in the spall zone.Deformation twins play an important role in forming and propagating the cleavage cracks in the targets.If the strength of the incident stress wave is much higher than the spall strength of the target,the cleavage cracks propargate more quickly to form a cleavage spall fractured surface.The influence of other microdefects on the dynamic fracture process and the mechanism of dynamic fracture modes of Ta-W alloy are also discussed in detail.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
1998年第1期32-36,共5页
Rare Metal Materials and Engineering
关键词
TA-W合金
层裂
晶间断裂
解理断裂
spall,intergranular fracture,cleavage fracture,fractured surface, Ta-W alloy.
