Hardness and tensile strength of zircon particles and TiB2 reinforced Al-A356. 1 alloy matrix composites :Comparative study

Aluminum matrix composites are important engineering materials in automotive, aerospace, thermal, wear, and other applications because of excellent low weight, high specific strength, and better physical and mechanical properties compared to pure aluminum. In this paper, zircon and TiB2 ceramic particles with different amounts were incorporated into Al-A356.1 alloy by stir-casting route. The ceramic particles size and adding temperature were 1 micron and 750°C respectively. Microstructure of samples has been investigated by scanning electron microscopy (SEM); hence the dispersion of reinforcement was noted. Situation of compounds of composites was examined by XRD. Mechanical tests such as hardness measurement, tensile and physical (density) tests were used. Results showed that the mechanical properties and microstructure behavior of composites have improved compared to monolithic alloy. Microstructures of the composites in as-cast conditions show uniform distribution particles and reveal better bonding in the case of zircon reinforced composite compare to TiB2, but increasing the amount of reinforcement shows better conditions in the case of TiB2 reinforced composite. It is observed that TiB2 reinforced composites have a better wetting condition compare to zircon reinforced composites.

Keywords:

Aluminum matrix composites , reinforcement , zircon , TiB2 , stir-casting , microstructure