Wear performance of the Fe-based alloy coatings produced by plasma transferred arc weld-surfacing process

Abstract

Two Fe-based gas atomized powders, proposed to as metamorphic alloys (Armacor M and Armacor C), were weld-surfaced by the plasma transferred arc (PTA) process. The resultant deposits were subsequently characterized using X-ray diffraction, scanning electron microscopy, and the microhardness tests. The wear performance of the two different coatings were investigated by the pin-on-disk dry sliding wear tests as well as three-body abrasive (DSRW) and two-body abrasive wear tests. Microstructural development during the solidification of each deposit is discussed. It is shown that Armacor M coating exhibits better wear performance than Armacor C coating for all wear testing investigated due to higher hardness and larger boride particles of Armacor M. The sliding wear resistance of both coatings follows a similar trend with the abrasive wear resistance. The wear rate of the pins for the pin-on-disk dry sliding wear testing is increased as the hardness of the counterpart disk is increased. It is also shown that wear rate and friction coefficient are the function of the applied stress. The XRD patterns in both the as-deposited coatings and worn surface do not show the presence of any significant amount of amorphous phase suggesting that crystalline–amorphous phase transformation has not occurred during the wear process.