Laser surface modification of ductile iron: Part 2 Wear mechanism

Abstract

A 10 kW CO2 continuous wave laser has been used to modify and refine the near surface microstructure of a ductile iron. The wear properties (evaluated by erosion, abrasion, and scratch tests) of the laser processed and unprocessed surfaces were studied. The wear resistance of laser processed samples is significantly enhanced by their refined austenitic microstructures and improved hardness in the melted and resolidified layer. The subsurface plastic deformation processes accompanying these wear tests are discussed. Cross-sectional scanning and transmission electron microscopy have been used to study the mechanism of wear particle generation. Subsurface microcrack generation and martensite formation from the mechanically metastable austenite matrix have been observed.MST/702