热处理对挤压态7090/SiC_p复合材料组织和力学性能的影响(英文)

采用喷射沉积的方法制备SiCp增强超高强Al-10%Zn-3.6%Mg-1.8%Cu-0.36%Zr-0.15%Ni复合材料。使用透射电镜(TEM)和能谱仪(EDS)对挤压并热处理过的合金棒进行微观组织取样观察。双级时效后的复合材料的晶粒比单级时效合金的晶粒更小。经单级时效处理,在晶界上和晶粒内部都可以观察到细小的η相和富AlZnMgCu 相的析出颗粒。双级时效后在 SiC 颗粒与基体的界面上发现了一层5nm厚的Si-Cu-Al-O非晶层。Ni、Zr的添加可以改善双级时效的效果,并且抑制7090/SiCp复合材料晶粒的生长。固溶时效处理可以显著提高复合材料的断裂韧性,而断裂韧性随着时效时间的延长而先减小后增加。

Effect of heat treatment on microstructure and mechanical property of extruded 7090/SiC_p composite

The ultra high strength SiC particles (SiCp) reinforced Al-10%Zn-3.6%Mg-1.8%Cu-0.36%Zr-0.15% Ni composite was prepared by spray co-deposition. Microstructures of the extruded and different heat-treated bars were analyzed by transmission electron microscopy (TEM) and energy dispersive spectrometry (EDS). Grain size of the composites prepared by two-stage solution is smaller than that by single-stage solution. After single-stage solution aging treatment, fine precipitates of both η and AlZnMgCu-rich phase can be found both intragranularly and intergranularly. While after the two-stage solution, an amorphous Si-Cu-Al-O (5 nm) layer appears at the interface. The addition of Ni and Zr modified the influence of the two-stage solution and inhibited the growth of the 7090/SiCp composite grain size. Heat treatments can significantly improve the fracture toughness of the composite. The fracture toughness first decreases then increases with the elongation of the aging time.