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对高体积分数碳化硅颗粒增强铝基(SiCP/Al)复合材料的拉伸、压缩和三点弯曲特性进行了实验研究。结果表明:高体积分数SiCP/Al复合材料与低体积分数SiCP/Al复合材料相比,没有明显的线性屈服阶段。进一步的加载-卸载实验表明,在外载荷作用下,材料宏观上呈现一种类似金属材料的塑性,卸载后留有较大的残余应变,再次加载时沿上次卸载路线上升,而且拉应力导致的残余应变大于压应力。三点弯曲时材料内部产生残余塑性变形的潜力最大,切线模量更稳定。宏观断口分析表明,金属基体的非均匀分布导致产生局部渐进的微屈服,是使材料性能宏观上类似塑性材料的主要原因。制备过程中的残余应力和基体内部的微缺陷是拉应力比压应力产生更大残余应变的主要原因。
The tensile, compressive and three-point bending properties of high volume fraction silicon carbide particle reinforced aluminum-based (SiCP / Al) composites were investigated experimentally. The results show that there is no obvious linear yielding phase for the high volume fraction SiCP / Al composites compared with the low volume fraction SiCP / Al composites. Further loading-unloading experiments show that under the external load, the material shows macroscopically plasticity similar to that of metallic materials, leaving larger residual strain after unloading and rising along the last unloading route when loading again, and the tensile stress Residual strain is greater than compressive stress. Three-point bending material within the residual plastic deformation of the greatest potential for the tangential modulus more stable. The macroscopic fracture analysis shows that the non-uniform distribution of the metal matrix leads to the local gradual micro-yielding, which is the main reason for making the material properties macroscopically similar to the plastic materials. Residual stresses in the preparation process and microdefects inside the matrix are the main causes of tensile residual stresses greater than compressive stresses.