Hybrid Metal Matrix Composites (HMMCs) have gained wide applications in aerospace, marine, and domestic areas because of its significant properties relative to external forces and enabling environment. In present research work, Ni-alloy selected as a matrix and Al2O3 of 40–80 μm and TiO2 of 1–5 μm were selected as reinforcements. The composites were prepared by keeping 9 wt. % of TiO2 as unvarying and Al2O3 is varied from 3 weight % to 12 weight % in steps of 3 weight %. Induction furnace is used for the casting of composites and mixing is done by using mechanical stirring at 160 rpm for a time period of 5 min. The prepared composites are then tested for their tensile and hardness as per the ASTM standards. The Scanning Electron Microscopy was used for microstructural study. From experimentation, it was observed that increment in the weight percentage of Al2O3 with constant TiO2 increases the mechanical properties of hybrid composites and proper stirring improves homogeneity in the composite material. The test results show that the addition of Al2O3 up to 9 weight percent increases in tensile strength compared to Ni alloy and tensile strength slowly decreases with the addition of Al2O3 and that the hardness values are directly proportional to the weight percent of the addition of Al2O3 / TiO2.

The current research aims to develop a hybrid metal matrix composition that focuses on the nickel alloy and its thermal properties. The different temperature ranges are used to analyze the function of MMCs such as thermal conductivity and coefficient of thermal expansion. This paper addresses the thermal properties obtained from a series of Al2O3 and TiO2 reinforced nickel alloy (ASTM A494 M), with dispersed particle sizes ranging from 40-45 microns of Al2O3 and 1-5 microns of TiO2. The quantity of the Al2O3 addition varies from 3-12 weight % and 9 weight % of TiO2 unvarying in the stages of three weight percentages. The microstructural investigation states that, because of the stir casting on the vortex, the distribution of reinforcements is uniform with a strong bond. With the increase in Al2O3 and TiO2 content in HMMCs, a thermal property is found to diminish significantly. The results indicate that the reinforcements have a major effect on the thermal expansion coefficient as well as on the thermal conductivity of the hybrid composites being produced. Various types of microstructural have been performed using electron microscopy scanning and EDAX. The limited examination of the exhaust valve of the I C engine shows that the nickel combination composites can be utilized as a substitute for the present valve material (Ni-Cr alloy steel). All tests acted in this investigation meet ASTM specifications.