Indian Journal of Science and Technology

Abstract

Objectives: This paper presents an influences of process parameters on micro hardness of electrodeposited Nickelslag powder composite coating based on Taguchi’s experimental design, signal to noise ratio and analysis of variances. Methods: Nickel – slag powder composite coatings are produced by conventional type electro deposition on mild steel substrate. The primary parameters; current density, pH, bath temperature, particle concentration and agitation speed are considered for experimental investigations. The experimental design is framed by L₂₇ orthogonal array of Taguchi’s model based on five parameters with three levels. The experiments are conducted in Watt’s type nickel bath. Findings: The micro hardness values of coating were determined using Vickers micro hardness tester. The micro hardness of the Ni-Slag coating was obtained in the span of 190 to 358 Hv. The significances of process parameters on micro hardness of coating were investigated with signal to noise ratio and analysis of variances, and ranked by order. It is observed that bath concentration and agitation speed are the most influencing factors on micro hardness. Application: Taguchi’s experimental approach reduces the experimental trails and contributing a greater advantage with reduced experimental time and cost of experimentation. Statistical investigations extend the reliability of an experimental work instead of conventional and randomized testing procedures. 
Keywords: Analysis of Variance, Composite Coating, Electrodeposition, Microhardness, Orthogonal Array, S-N Ratio