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为研究大塑性变形对金属基复合材料微观组织和力学性能的影响,利用高压扭转工艺(HPT)在200℃下将纯Al粉末和经氧化处理的SiC粉末混合固结成10wt%SiC_P/Al复合材料。采用TEM观察HPT变形后不同圈数试样的SiC-Al界面及Al基体微观组织,采用EDS能谱仪分析界面处原子扩散现象,采用万能拉伸试验机测试研究不同扭转圈数试样的力学性能。结果表明:不同圈数试样Al基体内出现大量位错、非平衡晶界等晶格缺陷;组织内存在两种SiC-Al界面,含SiO_2层的原始界面和因颗粒破碎而新生成的界面。两种界面结合良好,界面处元素相互扩散;随着扭转圈数的增加,10wt%SiC_P/Al复合材料抗拉强度增加,延伸率得到较大提高。分析发现高压扭转后不同圈数组织内产生的大量晶格缺陷和细小晶粒,促进界面处元素的相互扩散,使界面结合良好,同时大量晶格缺陷和细小晶粒的产生以及结合良好的SiC-Al界面是SiC_P/Al复合材料力学性能大幅提升的主要原因。
In order to study the effect of large plastic deformation on microstructure and mechanical properties of metal matrix composites, pure Al powder and oxidized SiC powder were mixed and consolidated into 10wt% SiC_P / Al composites by high-pressure twisting process (HPT) at 200 ℃ material. TEM was used to observe the microstructure of SiC-Al interface and Al matrix with different number of turns after HPT deformation. The atomic diffusion phenomenon at the interface was analyzed by EDS EDS. The mechanical properties of samples with different numbers of torsional cycles were tested by universal tensile testing machine performance. The results show that there are a large number of lattice defects in Al matrix with different number of laps, such as dislocations and unbalanced grain boundaries. There are two kinds of SiC-Al interface, the original interface with SiO 2 layer and the new interface . The interfacial diffusion between the two kinds of interface and the interfacial diffusion between the two kinds of interface; With the increase of the number of torsional turns, the tensile strength of 10wt% SiC_P / Al composites increases and the elongation increases greatly. It is found that a large number of lattice defects and fine grains are produced in different turns after high-voltage torsion, which promotes the interdiffusion of elements at the interface and makes the interface well bonded. Meanwhile, a large amount of lattice defects and fine grains are produced, -Al interface is the main reason for the substantial improvement of mechanical properties of SiC_P / Al composites.