Microstructural Evolution and Mechanical Properties of Al5083 Composite Reinforced with In-Situ TiB2 Particles

Microstructural evolution and mechanical properties of in-situ Al5083 composites with 1 and 5 volume percent of TiB2 reinforcement particles were investigated. It was revealed that hot extrusion process results in a uniform, more homogeneous and less clustered structure of TiB2 particles compared with the as-cast structures. Scanning electron microscopy showed that TiB2 particles in the Al5083-1 vol.% TiB2 composite have a nearly equiaxed morphology and round shape with an average size of ~ 0.5 µm. While, the morphology of TiB2 particles in Al5083-5 vol.% TiB2 composite is hexagonal with an average size of ~ 2 µm. Also, it was found that the grain size reduces by adding TiB2 reinforcement particles to the Al5083 alloy. It was shown that the hardness, yield strength, young’s modulus, and ultimate tensile strength of the Al5083-TiB2 composites increase with increasing TiB2 content. This can be attributed to the effect of TiB2 particles as a high hardness reinforcement phase and also the smaller grain size of the matrix which was resulted by adding the TiB2 particles.