高径比对W纤维/Zr基非晶复合材料压缩性能的影响

Effect of Length to Diameter Ratio on Compressive Properties of W Fiber/Zr-based Metallic Glass Composite

采用渗流铸造法制备W纤维/Zr基非晶复合材料,研究高径比的变化对复合材料室温压缩力学性能的影响。结果表明,复合材料的屈服强度随样品高径比的增大先降低,高径比大于1时趋于平稳。高径比大于或等于1.25时,复合材料的压缩塑性应变变化不大。高径比小于1.25时,复合材料的压缩塑性应变均大于50%。压头与样品端部摩擦力的作用、W纤维之间非晶丝高径比的变化和W纤维与非晶基体之间变形的不匹配综合作用最终导致小高径比的复合材料样品具有更好的压缩力学性能。

The W fiber/Zr-based metallic glass composite was prepared by infiltration and rapid solidification. The effect of the ratios of length to diameter of fibers on the compressive properties of the composite was investigated in detail. The results show that the yield strength firstly decreases with the increase of the length to diameter ratio then reaches a stable value when the ratio is greater than 1. The plastic strain has no obvious change when the ratio is greater than or equal to 1.25, while the plastic strain is bigger than 50% when the ratio is smaller than 1.25. The reason for these phenomena is the comprehensive effect of the friction force between pressure head and the end of the compressive sample, the change of the length to diameter ratio of the metallic glass fibers between W fibers and the mismatching between metallic glass matrix and the W fiber during deformation.