Influence of copper and molybdenum on dry sliding wear behaviour of sintered plain carbon steel

• Effect of Cu and Mo on wear behaviour of sintered Fe–0.5%C steel has been studied.
• Influence of loads and speeds on wear behaviour of the P/M alloys has been analyzed.
• Addition of Cu and Mo invariably improves the wear resistance of P/M steel.
• Formation of carbides significantly enhances wear resistance of Mo alloyed steel.

Study of wear behaviour of sintered low alloy steels is required to ascertain their applications for wear resistance. In the present work the influence of copper and molybdenum on wear behaviour of plain carbon steel (Fe–0.5%C) using pin-on-disk arrangement has been addressed. Atomized iron (Fe), graphite (C), copper (Cu) and molybdenum (Mo) elemental powders were suitably weighed and thoroughly mixed in a pot mill to yield the alloy powders of Fe–0.5%C, Fe–0.5%C–2%Cu and Fe–0.5%C–2%Mo. Admixed alloy powders were then compacted and sintered for obtaining preforms of aspect ratio (height/diameter) 1.3 and diameter 25 mm. The sintered preforms were then hot extruded and subsequently machined to obtain wear test specimens of diameter 6 mm and height 50 mm. Using Design of Experiment software, the sliding wear experiments were planned and conducted on a pin-on-disk tribometer. It has been found that there is a substantial improvement in wear resistance of the P/M plain carbon steel by the addition Mo rather than Cu. However coefficient of friction is higher due to presence of hard microstructural phases. Delamination wear is found predominant for both the alloy steels. Empirical correlations for mass loss and coefficient of friction with respect to load/speed have been developed for the alloy steels.