Corrosive Wear Behavior of 7075 Aluminum Alloy and Its Composite Containing Al_2O_3 Particles

摘要

Corrosive wear behavior of 7075 aluminum alloy and a composite containing 0.10 volume fraction of alumina particles (VFAP) has been evaluated. Transient current (TC) generated as a result of impacting a rotating cylindrical electrode immersed in a 0.1M NaCl solution with a Vickers diamond hardness indenter has been used to measure the corrosive wear response. Age hardenable 7075 alloy shows TC values that are sensitive to prior solutionizing time. The effect of alumina particles in a 7075 aluminum alloy matrix has been studied by comparing the TC values of a monolith along with composites under almost identical experimental conditions. The role of Microstructural features associated with composites, such as dislocations generated after solutionizing treatment and during the corrosive wear process, has been observed with the help of near surface microstructures through transmission electron microscopy (TEM). Deformation induced dislocations, as well as those that are due to differences in the coefficient of thermal expansion (CTE) values between the particles and the matrix during solutionizing, have been attributed to the experimentally observed TC values. They may also be affected by the aging response of the monolith and composites depending on solutionizing time.