Abrasive wear mechanisms of multi-components ferrous alloys abraded by soft, fine abrasive particles

In this paper, the effect of micro-structural parameters (eutectic carbides and matrix hardness) on the micro-abrasive wear of multi-component ferrous alloys abraded by soft, fine abrasive particles is analyzed. Two series of quenched and tempered alloys, with variable vanadium or molybdenum contents and fixed amounts of other elements, were tested. Each series includes an alloy free of carbides (matrix alloy) and alloys containing carbides (carbide rich alloys). Heat treatment produces three different levels of matrix hardness. Free ball micro-abrasion tests were conducted using SiO2 fine abrasives. The results showed that the wear coefficient was not influenced by neither the nature and amount of eutectic carbides nor by the hardness of the matrix. Matrix alloys showed a considerably higher micro-abrasive wear rate (up to 5 times) than eutectic carbide rich alloys. Special emphasis is given to the wear mechanisms, characterized by scanning electron microscopy and laser interferometry. Analysis of transversal sections produced by using Focused Ion Beam and High Resolution Scanning Electron Microscopy showed that the removal of matrix material due to abrasion with fine silica particles decreased the mechanical supporting of the carbides, which caused gradual fracture and their pull-out.