Wear behavior of different surface treated cam spindles

Abstract

In this study wear behavior of cam spindles made of five different surface treated nodular cast iron (GGG50) and induction hardened CK45 steels was investigated. In the experiments; PVD–TiN-coated, both borided and PVD–TiN-coated, only hardened, both hardened and PVD–TiN-coated and only borided spherical graphite cast iron and induction hardened CK45 were used. The wear behavior of two type of steel was observed using cam wear mechanism under unlubricated and six different surface treatments. AISI 4140 steel was used for abrasive plate. The boronizing process was realized in a salt bath consisting of borax, boric acid and ferro-silicon at 900 °C for 6 h and appropriate boronizing heat treatment was carried out under atmospheric pressure. Borides, e.g. FeB, and Fe 2B formed on ductile iron was verified by scanning electron microscope (SEM) and the distribution of alloying elements was detected by means of energy dispersive spectroscopy (EDS) from the surface to the interior. The weight loss amounts were determined as a function of sliding time and sliding velocity. In the result of the experiments; boriding and PVD–TiN coating were successfully applied to GGG50 spherical cast iron. These surface treatments increased the wear resistance of GGG50 material.