材料期刊网

Five-layered Al/Al-Cu functionally graded material (FGM) was prepared by powder metallurgy technology, and the subsequent heat treatment was carried out for the graded material. The microstructures and distribution of Cu element under pressure sintering (F), solution treatment (T4) and artificial aging treatment (T6) were investigated, and the Vickers hardness and flexural properties of different states were tested. The results showed that sintered compact with dense structure and compositional continuous change was obtained. The second-phase CuAl₂ was dispersively distributed along grain boundary of Al matrix. After solution treatment at 503℃ for 3 h, CuAl₂ phase obviously decreased and dissolved into the Al matrix, and the flexural strength was thereupon enhanced to 228.5~MPa. With the subsequent aging treatment at 150℃ for 15 h, the majority of flake shaped precipitates Θ" phases were uniformly distributed in the matrix. And the distribution of Cu element became gradual continuous compared to sintered compact. Meanwhile, the flexural strength increased further, which accompanied with the decline of plasticity.