钨丝增强铜基复合材料的动态力学性能及断裂特性

Dynamic Mechanical Properties and Fracture Characteristics of Tungsten Fiber Reinforced Cu-Based Composites

摘要:

通过渗流铸造的方法制备出Wf/Cu82Al10Fe4Ni4复合材料，采用分离式霍普金森压杆(SHPB)和扫描电镜(SEM)研究其动态压缩行为及断裂特性。结果表明：复合材料界面结合紧密，受冲击时体现出良好的界面结合强度；在应变率为2000 s-1下动态压缩材料发生部分塑性变形，局部表面出现裂纹；在应变率为3000 s-1下动态压缩材料的动态压缩强度达到2500 MPa，材料内部出现钨丝劈裂、钨丝弯曲断裂以及基体合金断裂3种破坏模式。同时，在材料的断裂面上出现大量熔化带，分析认为熔化是随着应变率的提高而出现的，它改变了复合材料的断裂方式，加速了Wf/Cu82Al10Fe4Ni4复合材料的整体失效

Abstract:

Tungsten fiber reinforced Cu82Al10Fe4Ni4 composites were prepared by a melt infiltrating casting method. Dynamic compression behavior and fracture characteristics were investigated by Split Hopkinson Pressure Bar (SHPB) and scanning electron microscopy (SEM). The results show that the interface between tungsten fibers and the matrix alloy is compact, and it exhibits high strength under dynamic compression. The composites create some plastic deformation and cracks under dynamic compression at strain rate of 2000 s-1. The dynamic compressive strength of the composites is 2500 MPa under dynamic compression at strain rate of 3000 s-1, and the failure modes of the composites include splitting and buckling of tungsten fiber and abruption of the matrix alloy. Meantime, the fracture surface creates lots of melting bands, which change the fracture mode of the composites and accelerate its failure