高冲击压力下93W合金的位错亚结构及其硬化特征

Dislocation substructures and hardening characteristics of 93W tungsten alloy under high shock pressure

采用宏观与显微硬度测量及位错亚结构观察分析相结合的方法对 93W合金真空退火处理态材料在爆炸冲击作用下的硬度变化及其机理进行了研究。发现 ,随着冲击压力的提高存在着一个由冲击硬化到软化的转化压力。该转化现象被位错亚结构随冲击压力的演化所证实。分析表明 ,在爆炸冲击下 ,材料剧烈的塑性变形效应在压力较低时应变硬化占主导地位 ,高冲击压力时塑性功转化为热所引起的温升 。

The hardness change of 93W tungsten sintered alloy under high shock pressure and its mechanism were investigated by means of macrohardness and microhardness measurement combined with dislocation substructures observation.The experimental results show that,in pace with the increase of shock pressure, a transition from shock hardening to softening occurs,which has been verified by the evolution of dislocation substructures.In addition, this paper also shows that the temperature rise caused by the violent plastic deformation and the formation of new separated phase in tungsten grains under explosive loading both are the possible reasons leading this alloy softening.