Effect of Cryogenic Chill on Dendrite arm spacing, Ultimate tensile strength and Hardness of ASTM A 494 M Grade Nickel alloy Metal Matrix Composites

This paper describes the obtained results and the data withdrawn from the set of microstructure and mechanical properties of metal matrix composites developed using cryogenically cooled copper chills, consisting of ASTM A 494 M grade nickel alloy matrix and garnet particles as the reinforcement which was sand cast using a cryogenically cooled copper chill sides. The effect of cryogenic cooling rate on the dendrite arm spacing (DAS), ultimate tensile strength (UTS) and the Hardness were evaluated. It was found that the ultimate tensile strength is highly dependent on the rate of cryogenic effect and chilling which determines the dendrite arm spacing of the material. Attempts were also made in this paper to explain these effects and to correlate the UTS and hardness with DAS. Furthermore, it was found that UTS and Hardness increases as DAS decreases.