应变率和相对密度对泡沫SiCp/ZL104压缩性能的影响

对采用熔体发泡法制备的泡沫5%(体积分数,下同)SiCp/ZL104复合材料进行了准静态和动态压缩性能的测试和分析.结果表明:无论是动态下压缩还是准静态下压缩,泡沫5%SiCp/ZL104复合材料的应力-应变曲线都呈现出典型的3个阶段:线弹性段、平台段和致密段;屈服应力对应变率很敏感,使得应变率增加时,屈服应力增加,且有应变硬化现象发生;随着相对密度的增大,泡沫5%SiCp/ZL104复合材料的动态屈服应力和流动应力与准静态载荷相比显著增加.

Effects of Strain Rate and Relative Density on Compressive Properties of SiCp/ZL104 Composite Foams

The quasi-static and dynamic compressive properties of 5vol%SiCp/ZL104 composite foams, fabricated by the method of direct melt foaming, were tested and analyzed. The results show that under the conditions of quasi-static or dynamic compression, the stress-strain curves of 5vol%SiCp/ZL104 composite foams involves three regions: the linear elastic deformation region, the collapse plateau region and the densification region. The yield stress is sensitive to the strain rate, so it increases and the strain hardening occurs with the increase of the strain rate. Compared with that under quasi-static loading, dynamic yield stress and flow stress of 5vol%SiCp/ZL104 composite foams increase remarkably with the increase of relative density.