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论文类型：期刊论文

发表时间：2019-01-28

发表刊物：MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

收录刊物：SCIE

卷号：744

页面范围：682-690

ISSN号：0921-5093

关键字：Al matrix composite; Powder metallurgy; Aging treatment; Tensile deformation; Strengthening mechanism

摘要：The effects of B4C particle (B4Cp) content and aging treatment on the microstructure and mechanical behavior of B4Cp/6061Al composites prepared by powder metallurgy were investigated. The results demonstrated that the relative density of the B4Cp/6061Al composites decreased slightly by increasing reinforcement content from 0 to 15 wt%. No obvious pores or reaction products were observed at the B4Cp/matrix interfaces by transmission electron microscopy, suggesting that a good, clean interface was achieved. Mg2Si precipitates and dislocations were detected both near the interfaces and in the matrix. Moreover, the aging kinetics could be significantly accelerated by the presence of B4C particles; this behavior was associated with the enhanced dislocation density. The variation in hardness and electrical conductivity as a function of aging time in composites with various B4Cp contents was examined. For the peak-aged composites with increasing B4Cp content from 0 to 15 wt%, the ultimate tensile strength increased from 342.2 to 451.0 MPa, whereas the failure strain decreased from 18.4% to 7.9%. The grain refinement, dislocation strengthening, and work hardening, which contributed to the improvement in yield strength, were theoretically calculated, and the results agreed well with the experimental results.