Reinforcements, production techniques and property analysis of AA7075 matrix composites − a critical review

Aluminium alloy based metal matrix composites are being extensively used in the aerospace, automobile, defense, marine and electronic industries owing to their excellent strength, high resistance to wear, corrosion and better thermal stability. Many investigators have explored different aluminium alloy series composites, like heat treatable AA2024, AA6061 and AA7075 since the properties of these matrix alloys can be easily tailor made to suite specific application due to easy processability and heat treatability. AA7075 alloy matrix is predominantly being used, as it exhibits high ultimate tensile strength, resistance to corrosion and fatigue in the group. In the current review work, attention is focused to present types of reinforcing materials used, benefits of reinforcement hybridization, methods employed for composite production and critical property analysis, with conclusions of experimentation and the suggested prospective applications of AA7075 composites. Due to good castability and moldability variety of processing techniques in solid, semisolid and liquid states are possible. As matrix alloy, low processing temperature, ability to accommodate reinforcements and adoptability to different reinforcing techniques, it is easy to obtain optimal properties as per the application. AA7075 with small addition of copper is paved the path in the field of electronic and military applications due to high thermal and electrical conductance. Even pure metal addition & magnesium with copper facilitate good weldability, plasticity and corrosion resistance. Due to the flexibility in accommodating carbide and oxide compound reinforcements in the matrix, this matrix composite widens versatility limit due to excellent hardness and wear resistance. CNT and graphite reinforcements to this aluminium series matrix are marked as ultra-high precision components in defense field.