The TiN/Ni composite coatings were deposited on 7005 aluminium alloy by high speed jet electroplating and then processed with plasma transferred arc(PTA)scanning process.The microstructure,microhardness and friction coefficient of PTA scanning treated specimens were investigated.It is shown that the PTA scanning treated specimens have a rapidly solidified microstructure consisting of the uniformly distributed TiN phase and fine Al3Ni2 intermetallic phases.The composite coating has an average microhardness of approximately HV 800.The friction coefficient of PTA scanning treated specimens(oscillated at around 0.25)is considerably lower than that of TiN/Ni composite coating(oscillated at around 0.35).The corrosion behavior of the composite coating in 3.5%NaCl solution at room temperature was also determined using a potentiostat system.In comparison with the corrosion potentialφcorr of-0.753 V for 7005 aluminium alloy,the corrosion potentials for TiN/Ti composite coating and PTA scanning treated specimen are increased by 0.148 V and 0.305 V,respectively.The PTA scanning treated specimen has the lowest corrosion current density Jcorr as well as the highest corrosion potentialφcorr,showing an improved corrosion resistance compared with 7005 aluminium alloy. The TiN / Ni composite coatings were deposited on 7005 aluminum alloy by high speed jet electroplating and then processed with plasma transferred arc (PTA) scanning process. Microstructure, microhardness and friction coefficient of PTA scanned treated specimens were. Ltt shown shown the PTA scanning the specimens for a rapidly solidified microstructure consisting of the uniformly distributed TiN phase and fine Al3Ni2 intermetallic phases. The composite coating has an average microhardness of approximately HV 800. The friction coefficient of PTA scanning treated specimens (oscillated at around 0.25) is considerably the corrosion behavior of the composite coating in 3.5% NaCl solution at room temperature was also determined using a potentiostat system.In comparison with the corrosion potential φcorr of-0.753 V for 7005 aluminum alloy, the corrosion potentials for TiN / Ti composite coating and PTA scanning The treated specimens were increased by 0.148 V and 0.305 V, respectively. The PTA scanned treated specimens had the lowest corrosion current density Jcorr as well as the highest corrosion potential φ corr, showing an improved corrosion resistance compared with 7005 aluminum alloy.