Development of aluminum hybrid metal matrix composite for aerospace application

Abstract

Among contemporary engineering applications as a high potential, light weight alternatives of commercially used conventional metals like steel and copper due to the enhanced thermal stability and general properties like high fatigue and wear resistance. It also possess further more superior properties like hardness and toughness along with improved mechanical properties when it is incorporated with different reinforcements in to its microstructure. This present research intended to experiment and fabricate advanced hybrid aluminium metal matrix composites via bottom pouring type stir casting furnace by adopting six unique feeding methods like regular feeding, two step feeding, capsulate feeding, pre-melt feeding, double layer feeding and novel Modified Matrix Encapsulated Feeding (MMEF). Silicon Carbide (SiC), alumina (Al2O3) and magnesium oxide (MgO) are utilized as filler materials in order to enhance the matrix strength. The main object is to choose optimum filler, filler ratio and feeding method through various combinations of hybrid configurations. Initially in phase I experiment AA7073 along with 2.5 wt. % of Al2O3 was fabricated by above mentioned feeding techniques to grasp its mechanical, wear and micro structural properties. From the results it was observed that MMEF method possess better properties. Based on the results in phase II 7075/SiC/Al2O3/MgO hybrid composites with varying weight percentage of SiC, Al2O3 and MgO was fabricated (via MMEF) and its results were discussed along with the SEM images. Taguchi optimization was also carried out to grasp the optimum process parameters that possess better tribological behaviour. From the results it was observed that there is a significant improvement in the mechanical and wear behavior of the 3 wt. % SiC, Al2O3 and MgO filled configurations. The proposed outcome of AMMCs shows enhanced properties which paws the way to use it in the high intensive aerospace applications like washers, rings, nose gear doors, slat track and wing lateral panels. newline