加载方式对Zr基非晶复合材料变形行为的影响

Effect of Loading Mode on Deformation Behavior of Zr Matrix Amorphous Composites

制备了含有8at%Ta元素的Zr基相应的非晶复合材料和Zr基完全非晶合金,研究了其在压缩和弯曲两种加载方式下的变形行为。结果发现,在压缩过程中,Ta固溶体粒子的存在可以阻碍剪切带的扩展,促使多重剪切带的萌生。因此,Ta固溶体相的存在可以有效的改善非晶合金的压缩塑性而不降低其强度;弯曲加载过程中,由于Ta固溶体和非晶基体的模量以及强度差异,两者的界面处会产生大的应力集中,在连续载荷的作用下,裂纹迅速沿着两者的界面形成并开裂,最终导致该非晶复合材料的失效,同时,相比于完全非晶合金,其断口上的临界剪切位移显著减少,且与Ta固溶体相的尺寸相当,因而Ta固溶体相的存在降低了非晶合金的弯曲塑性变形能力。

Zr matrix amorphous composites containing 8 at%Ta and completely Zr matrix amorphous alloy were prepared.The deformation behavior of the composites under compression and bending loading was investigated.The results show that,the existence of Ta solid solution particles can hinder the propogation of shear band and promote the initiation of multiple shear bands.Therefore,the existence of Ta solid solution phase can effectively improve the compressive plasticity of amorphous alloy without decreasing its strength.During bending loading,due to the difference of modulus and strength between Ta solid solution and amorphous matrix,there is large stress concentration at the interface of Ta and amorphous matrix.Under the action of continuous load,the crack forms rapidly along the interface of both phases,which results in the failure of the amorphous composite.At the same time,compared with the completely amorphous alloy,the critical shear displacement on the fracture surface is significantly reduced,it is similar to that of the Ta solid solution phase.Therefore,the existence of Ta solid solution phase reduces the bending plastic deformation ability of amorphous alloy.