Title: Effect of process parameters on the microstructure, hardness and wear resistance properties of Zn-Sn-Ti coatings on AISI 1015 steel: laser alloying technique
Authors: Olawale S. Fatoba; Esther T. Akinlabi; Mamookho E. Makhatha
Addresses: Department of Mechanical Engineering Science, Faculty of Engineering and the Built Environment, University of Johannesburg, South Africa ' Department of Mechanical Engineering Science, Faculty of Engineering and the Built Environment, University of Johannesburg, South Africa ' Department of Metallurgy, Faculty of Engineering and the Built Environment, University of Johannesburg, South Africa
Abstract: The deterioration of materials during industrial application poses a serious threat to the materials structural integrity. A material's susceptibility to wear and surface damage can be reduced by alteration of its surface chemistry, morphology and crystal structure which plays an important role in optimising a material's performance for a given application. The aim of the research was to investigate the enhancement in the microstructure and wear property of Zn-Sn-Ti ternary coatings on AISI 1015 steel by laser alloying technique using Ytterbium laser system (YLS). A laser power of 750-900 W, scanning speeds of 0.6 and 0.8 m/min, and alloy compositions of 25Zn-25Sn-50Ti and 20Zn-20Sn-60Ti were used in this study. At optimum composition of 20Zn-20Sn-60Ti and speed of 0.8 m/min, there was enhancement of 24% in wear resistance performance which was attributed to metastable intermetallic phases. The coatings were free of cracks with homogeneous and refined microstructures and good adhesion to the substrate. The response surface model (RSM) used authenticates reasonably with the experimental results.
Keywords: AISI 1015; Zn-Sn-Ti coatings; wear resistance; microstructure; response surface model; RSM.
International Journal of Surface Science and Engineering, 2017 Vol.11 No.6, pp.489 - 511
Received: 01 Mar 2017
Accepted: 17 May 2017
Published online: 29 Dec 2017 *