钨丝增强Zr基非晶复合材料动态力学行为及断裂特性

Dynamic mechanical behaviors and fracture characteristic of tungsten fiber reinforced Zr-based metallic glass matrix composites

采用渗流铸造法制备出d 6 mm钨丝增强ZrTiCuNiBe非晶合金复合材料,并利用Hopkinson压杆冲击加载装置、X射线衍射仪(XRD)和扫描电镜(SEM)等手段研究其动态压缩行为及断裂特性。结果表明:随着钨丝直径减小和体积分数的增加,材料的动态压缩强度增大;当钨丝直径为0.25 mm,体积分数为60%时,材料的动态压缩强度高达2 600 MPa,断裂模式为剪切断裂和劈裂混合破坏模式,同时有钨丝与基体发生脱粘现象。非晶基体在动态压缩条件下表现出显著的热软化和熔化特征。

Tungsten fiber reinforced ZrTiCuNiBe metallic glass composites were fabricated by melt infiltrating casting method. The samples are 6 mm in diameter with aspect ratio of 1. They were tested by using Hopkinson pressure bar, SEM and XRD. The experimental results show that the dynamic compressive strength increases both with increasing volume fraction of W fiber and decreasing tungsten fiber diameter. The dynamic compressive strength of the composites is 2 600 MPa when the tungsten fibers are 60% in volume fraction and 0.25 mm in diameter. The failure mode is a mixed fracture mode consisting of share and splitting. The delamination of tungsten fibers are also found in the matrix. The typical melt and thermal-softening characteristic of Zr-based metallic glass matrix are found in the dynamic compressive process.