Effect of functional composite coating developed via sulphate and chloride process parameter on the UNS G10150 steel for structural and wear mitigation in defence application

The major engineering challenge of materials in defence technologies is the vulnerability of based metals to structural and wears deformation in service. In this paper, structural formation, mechanical and thermal stability behavior of developed composite coating of Zn-30Al-7%Ti/Sn chloride bath and Zn-30Al-7%Ti/Sn sulphate bath was investigated and compared to provide mitigation against failure. The thermal ageing property was done for 2 h at 600 °C via isothermal furnace. The structural, interfacial effect and stability behaviors of the co-deposited alloys were evaluated using scanning electron microscope equipped with energy dispersive spectrometer (SEM/EDS), atomic force microscope (AFM) and X-ray diffractometer (XRD). The hardness and wear properties of the deposited coatings were examined with diamond base micro-hardness tester and reciprocating sliding tester respectively. The result shows that Zn-30Al-7%Ti/Sn sulphate co-deposition contributed to increase hardness and wear resistance than Zn-30Al-7%Ti/Sn chloride bath alloy. The stable crystal growth and significant performance of Zn-30Al-7%Ti/Sn sulphate are link to the intermetallic phase hybrid of ZnAl, Zn4TiAl2, Zn3AlTi. Besides, it was observed that Zn-30Al-7%Ti/Sn sulphate has excellent thermomechanical stability at harsh temperature, due to the deposition of Sn/Ti on steel; leading to formation of super-hard interface. However, it was established that co-deposition of mild steel with Zn-30Al-7%Ti/Sn in sulphate bath significantly improved the structural and wear performance. It was shown that the hardness and wear of the developed composite Zn-30Al-7%Ti/Sn is increased by about 80% compared to as received sample and about 25% compared with Zn-30Al-7%Ti/Sn chloride coating developed. The improvement was proved to be an interference of zinc-composite growth. Thus, this work shows that sulphate induced Zn-30Al-7%Ti/Sn via generation of controllable process parameter can provide significant improvements in thin film coating for wear mitigation and structural improvement in defence application.