Optimization of tribological parameters over WC-12%Co laser alloyed pearlitic ductile iron using Taguchi based Grey relational analysis

Abstract

Pearlitic ductile irons (PDIs) are used in transportation and nuclear energy industries. In heavy loading situation, the service life of PDI is affected by numerous tribo aspects. In this study, surface of the PDI is alloyed with WC-12%Co powder using a high power fibre laser. The wear properties of the base material and laser alloying samples were investigated by tribometer with various parameters, i.e., temperature, load and sliding speed. Based on experimental test, the load has maximum percentage of contribution and followed by sliding speed and working temperature. The optimized tribological parameters by Grey relational analysis (GRA) were established and those values are closely matched with predicted values. Besides, base material and laser alloying surfaces were examined through Vickers hardness machine, scanning electron microscopy (SEM) and roughness tester. The laser altered specimen shows no defects and improves the wear properties than substrates. The identified optimal tribological parameters are load of 30 N, speed of 0.5 m/s and working temperature of 300 °C, and load of 30 N, speed of 0.5 m/s and working temperature of 200 °C for base metal and laser alloying samples, respectively.