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利用分离式霍普金森压杆(SHPB)对颗粒体积分数为50%的颗粒增强金属基复合材料SiCp/2024Al进行了动态压缩试验,并得到了应变率范围为1250/s―2500/s的动态应力-应变曲线,且与准静态压缩下的结果进行了对比。实验中根据SHPB理论假设,采用波形整形技术,使得试件在加载过程中处于应力平衡和均匀变形状态。试验结果表明:随着应变率的增大,与准静态结果相比,在高应变率下复合材料的流动应力和塑性应变有明显的增大,具有显著的应变率敏感率,且破坏形式表现出脆性特征。试件断口扫描电镜实验结果发现基体由于绝热压缩生成的热而发生了明显的熔化现象。该文还讨论了应变率和颗粒体积分数对复合材料破坏模式和变形机理的影响。
The dynamic compressive test of SiCp / 2024Al with 50% particle-size particle reinforced metal matrix composites was carried out by using split Hopkinson pressure bar (SHPB). The dynamic strain rate range of 1250 / s-2500 / s Stress-strain curve, and compared with the results under quasi-static compression. According to the hypothesis of SHPB theory in the experiment, the waveform shaping technique was used to make the specimen in the state of stress equilibrium and uniform deformation during loading. The experimental results show that with the increase of strain rate, compared with the quasi-static results, the flow stress and plastic strain of composites increase obviously with high strain rate, with significant strain rate sensitivity, and the failure forms A brittle character. Specimens fracture SEM results showed that the matrix melted obviously due to the heat generated by adiabatic compression. The article also discusses the effect of strain rate and particle volume fraction on the failure mode and deformation mechanism of composite materials.