The Size Effect in Abrasion of Dual-Phase Alloys

Abstract

The abrasion rate of an alloy has generally been found to be a function of the abrasive particle size, decreasing rapidly for particle sizes below about 100 microns, and the same general behavior is found for erosion by solid particle impact. Most previous investigations of this effect have been confined to single-phase alloys or steels having second-phase particles which are small relative to the size of the surface grooves. In the present study, a dual-phase powder-metallurgy alloy (Stellite 19) was abraded with both quartz and alumina abrasives using a low-stress abrasion test, and 1020 steel specimens were also included as a comparative standard. The quartz abrasive particles have a hardness intermediate between that of the Stellite 19 matrix and the large, hard Cr-rich carbides which are contained in the microstructure, whereas the alumina particles have a hardness comparable to that of the carbides.

The alumina abrasion test results show that both Stellite 19 and 1020 steel respond to abrasive particle size in much the same manner as that observed by previous investigators. The 1020 steel also exhibited a typical size effect for the quartz abrasive, whereas the quartz abrasion rate of the Stellite 19 actually increased with decreasing particle size rather than decreasing. These results can be explained in terms of the fact that the primary mechanism of material removal was micromachining for the cases in which the usual size effect was observed, while the material removal rate in the case of abrasion of Stellite by quartz is controlled by carbide microfracture.

Presented at the 39th Annual Meeting in Chicago, Illinois May 7–10, 1984

Notes

Presented at the 39th Annual Meeting in Chicago, Illinois May 7–10, 1984