Effects of pre- and post-friction surfacing heat treatment on microstructure and corrosion behavior of nickel-aluminide reinforced Al-Cu-Mg alloy

In this research, the effect of pre-heat treatment of mechtrod and post-processing heat treatment of coating on the microstructure and corrosion behavior of the nickel-aluminide reinforced Al-Cu-Mg alloy coating has been studied. Results show that under a similar heat treatment condition of mechtrod, no significant difference is observed in the coating efficiency of the samples with and without nickel-aluminide reinforcement. The presence of nickel-aluminide intermetallic has acted as a barrier to grain growth, preventing it from occurring to a large extent. After aging heat treatment, the abnormal grain growth (AGG) on a large scale and the AGG and normal grain growth (NGG) in coatings without and with nickel-aluminide, respectively, are well confirmed by Humphreys' model. After artificial aging, the presence of nickel-aluminide reduces the formation of S-Al2CuMg precipitates. Using solid solutionized consumable rod, the corrosion resistance of artificially aged nickel-aluminide containing coating is 64% and 59% higher than Al-Cu-Mg alloy substrate and artificially aged nickel-aluminide free coating, respectively.