纤维体积分数对W纤维/Zr基非晶合金复合材料压缩性能的影响

采用渗流铸造法制备了含不同体积分数W纤维的W_f/Zr基非晶合金复合材料,其中W_f体积分数分别为47%、66%、77%和86%。研究了W_f体积分数对Zr基非晶复合材料室温准静态压缩力学性能以及变形行为的影响。结果表明:随W_f体积分数的增加,W_f/Zr基非晶复合材料的屈服强度单调增大,塑性应变先增大后减小,W_f体积分数为66%时塑性应变最大,W_f/Zr基非晶复合材料塑性应变的变化主要取决于非晶基体和W_f相互作用的程度。随着应变量的增大,基体中剪切带的数量和密度也随之增大,主剪切带向大于45°方向偏转。由于压头的影响,W_f/Zr基非晶复合材料压缩过程中样品端部和中部的受力状态不同,导致两部分的剪切带方向也明显不同。随W_f体积分数的增大,W_f/Zr基非晶复合材料的断裂方式由剪切断裂向纵向劈裂转变,断裂行为符合摩尔库伦准则。

Effect of fiber volume fraction on the compressive properties of the W fiber/Zr-based metallic glass composites

The W fiber Wf/Zr-based metallic glass composites with different fiber volume fraction VF were prepared by infiltration and rapid solidification.The VF were 47％,66％,77％ and 86％％,respectively.The effect of VF on the quasi-static compression mechanical properties and deformation behavior of the Wf/Zr based metallic glass com posites was researched in detail.The results show that the yield strength of the Wf/Zr-based metallic glass composites increases with increase of the VF.The plastic strain firstly increases and then decreases with increase of the VF.The plastic strain is the largest when the VF is 66％.The change of the plastic strain in the Wf/Zr-based metallic glass composites mainly depends on the interaction between matrix and Wf.With increase of strain,the quantity and density of the shear bands in the matrix increase,and the main shear band deflects towards the direction more than 45°.The stress state in the end and middle of the Wf/Zr-based metallic glass composites sample is different during compression because of the influence of the pressure head,which results in the direction of the shear bands difference in different areas of the sample.The failure modes of the Wf/Zr-based metallic glass composites change from shear fracture to longitudinal splitting with the increase of the VF.The fracture behavior the Wf/Zr-based metallic glass composites complies with the Mohr-Coulomb criterion.