Influence of TAC/Ti/Si3N4 on mechanical and corrosion performance of AA7075 alloy matrix composite processed by stir processing route

Abstract

In modernistic years, Metal Matrix Composites (MMCs) are becoming enchanting in fields of aerospace, military, defence and automobile applications reason being they offer merit such as high strength to weight proportion, good tribological, good corrosion resistance, excellent fatigue and creep performance and good bending behaviour etc. In the current research, an attempt was made to synthesize AA7075 blended with distinct wt% of Titanium (Ti), Tantalum Carbide(TaC) and Silicon Nitride (Si₃N₄) multi hybrid MMCs were examined. Microstructural, flexural, corrosion and low cyclefatigue aspects of the developed multi hybrid MMCs were examined as per ASTM standard. The brittleness of Si₃N₄, TaC and Ti particulates structured with the interface betwixt matrix culminates in increment in the flexural strength of thecomposite. The bending analysis clearly shows that, TaC and Si₃N₄ are the major contributing materials for flexural aspect because the presence of hard ceramic particulates restricts the dislocation movement by providing additional strength. Microstructural analysis reveals the existence of reinforcements. Also, homogeneous dissemination and good interfacial bonding betwixt the matrix and reinforcement particulates were noticed. AA7075 reinforced with 1 wt% Ti, 6 wt% Si₃N₄ and 0.5 wt% TaC operated at higher load (1500 N) and higher number of cycles 14x10³ cycles with a stable strain rate. Thenumber of cycles to failure was observed to be enhanced for the matured composites on account of an inconsequential percentage of induced plastic strain.