THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE
THE REINFORCING MECHANISM OF TiB2 IN TiB2／A357 COMPOSITE

Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Microstructures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200)A1 and (101)TiB2 with 011]Al // 101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0. 1ηm in diameter and dislocation multiplication near TiB2 particles.