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采用无压浸渗的方法制备了陶瓷(Si3N4p)含量为34.4%、46.3%和51.4%的3种Si3N4p/Al复合材料,应用分离式霍普金森压杆装置测试了复合材料在不同应变率下的动态压缩性能,并与准静态压缩性能进行了比较。分析了应变速率和陶瓷含量对复合材料动态性能的影响规律,探讨了复合材料微观组织特征对复合材料动态性能的影响机制。研究结果表明,Si3N4p/Al复合材料的动态压缩强度高于准静态压缩强度;在动态压缩过程中,高应变率载荷导致复合材料铝合金基体中具有高位错累积速率和较高的温升,因而复合材料动态压缩响应表现为“应变率硬化”效应和“热软化”效应的耦合。复合材料的动态压缩强度随着陶瓷含量增加而增加;热软化效应则随陶瓷含量增加、铝合金变形能力下降而相应减弱。
Three kinds of Si3N4p / Al composites with Si3N4p content of 34.4%, 46.3% and 51.4% were prepared by pressureless infiltration method. The composites were tested at different strain rates by using split Hopkinson pressure bar device The dynamic compression performance is compared with the quasi-static compression performance. The influence of strain rate and ceramic content on the dynamic properties of the composites was analyzed. The influence of the microstructure of the composites on the dynamic properties of the composites was also discussed. The results show that the dynamic compressive strength of Si3N4p / Al composite is higher than that of quasi-static compressive strength. During dynamic compression, the high strain rate loading leads to high dislocation accumulation rate and high temperature rise in the composite aluminum alloy matrix The dynamic compression response of composites shows the coupling of “strain rate hardening” effect and “heat softening” effect. The dynamic compressive strength of the composites increases with the increase of the ceramic content. The thermal softening effect decreases with the increase of the ceramic content and the deformation ability of the aluminum alloy.