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对粉末冶金法制备的15%(原子分数)SiCp/2009Al复合材料进行超声无损检测,将超声检测过程中发现的当量在0.8~0.9 mm之间的颗粒分布不均匀型缺陷制成含缺陷的拉伸试样进行性能测试,并制作了不含缺陷的试样进行对比。实验结果表明含有缺陷的试样未断在缺陷位置处,试样性能表现出高强度和良好的塑性,与无缺陷试样拉伸性能基本没有差别。进一步研究表明,断口处为正常组织。基体上的韧窝说明试样断裂过程中存在韧性断裂。小韧窝、SiC颗粒的解理断裂和开裂现象的存在说明应力能够有效地从基体转移到颗粒上,颗粒增强的作用得到了充分的发挥。因此,试样表现出高强度和良好的塑性。当增强颗粒与基体结合良好时,增强颗粒可以很好的承载基体转移过来的应力,而且,由于聚集处碳化硅颗粒的含量比正常组织的含量要大,增强效果更明显,使得缺陷处的强度可能高于正常组织的强度,导致试样在正常组织处发生断裂。总之,在实际生产中,如果对铝基复合材料制品进行超声无损检测时发现含有当量小于0.9mm的颗粒分布不均匀型缺陷,制品的拉伸性能仍满足使用要求。
Ultrasonic non-destructive testing of 15% (atomic fraction) SiCp / 2009Al composites prepared by powder metallurgy was used to fabricate a defect-laden defect with nonuniform distribution of particles with an equivalent weight of 0.8-0.9 mm found during ultrasonic testing Tensile specimens for performance testing, and produced a defect-free samples for comparison. The experimental results show that the samples with defects are not broken at the defect position, the samples show high strength and good ductility, which shows no difference from the tensile properties of the non-defective samples. Further research shows that the fracture at normal tissue. The dimples on the substrate indicate the presence of ductile fracture during fracture of the specimen. Small dimples, SiC particles cleavage fracture and the presence of cracking phenomenon shows that stress can be effectively transferred from the matrix to the particles, the role of particle enhancement has been fully played. Therefore, the specimen showed high strength and good ductility. When the reinforcing particles are well bonded with the matrix, the reinforcing particles can well carry the stress transferred by the matrix, and the strengthening effect is more obvious because the content of the silicon carbide particles in the aggregation is larger than that in the normal tissue, so that the strength at the defects May be higher than that of normal tissue, causing the sample to rupture at normal tissue. In short, in actual production, if the non-destructive testing of aluminum-based composite products by ultrasonic non-destructive testing found that the equivalent particle size distribution of less than 0.9mm uneven defects, the tensile properties of the products still meet the requirements.