硼酸铝晶须增强6061铝合金复合材料的断口分形分析

摘要

The effect of interface reaction on the fractal dimensions of fracture surface in aluminum borate whisker-reinforced aluminum alloy 6061 composite was investigated. The composite was fabricated by squeeze-casting technique. The fracture surfaces created in tensile test were measured by vertical sectioning method. Fractal phenomena were found in two plots,in which the measuring units were from 3 to 15 μm and 1 to 5 μm,respectively. The relation was established between the tensile properties and fractal dimension with measuring units of 3-15 μm. The results show that the ultimate tensile strength increases while the fracture surface roughness increases with fractal dimension increasing due to the change in fracture mode depending on the degree of interface reaction status induced by heat treatment. But when the measuring units are 1-5 μm,fractal dimension does not change with heat treatment.%硼酸铝晶须增强6061铝合金基复合材料中的界面反应影响其断口分形维数.该复合材料由压力铸造法制备,采用垂直剖面法分析拉伸断裂断口.当量尺度分别取3-15μm以及1-5μm时,可以在断口上发现分形现象.当量尺度在3-15μm的分形域,其分形维数与材料抗拉强度显著正相关.实验结果表明,随热处理时间的延长,界面反应产物的分布与状态可以改变材料的微观断裂模式,进而影响断口的粗糙度和分形维数,同时决定材料的抗拉强度.而当量尺度为3-15 μm的分形域,其分形维数受热处理程度的影响不很显著.