Microstructure and Mechanical Properties of Al-Ni Alloy for High Pressure Die Casting

Al-Ni alloys have been proven to be promising cast aluminum alloys for high-temperature applications, due to their high thermal stability and good castability. This research investigated the microstructure and mechanical properties of Al-6Ni alloy produced by high pressure die casting process. Tensile and hardness tests were conducted on the as-cast samples. Microstructure and fracture surface of the alloys were analyzed by optical microscope (OM) and scanning electron microscope (SEM). Results indicated that the microstructure of Al-6Ni alloy consists of two phases of α-Al and Al-Al₃Ni eutectic. The as-cast alloy tested at room temperature showed the yield strength of 87 MPa, ultimate tensile strength of 179 MPa, elongation of 14% and hardness of 55 HV. The result indicated that the Al-6Ni eutectic alloy could be produced by the high pressure die casting process and could be considered as an alternative aluminum casting alloy for engineering applications.