Abstract
Arc sprayed coatings are attractive means to protect components from abrasion wear provided they contain enough hard phases. Because of their hardness and toughness 316LTiB2 cermets were selected as the basis for developing wear resistant coatings. Core wires composed of 304 stainless steel sheaths filled with 10 to 65 wt % TiB2, 1 to 15 wt % additives and remaining 316L stainless steel were fabricated and arc sprayed with air. The arc sprayed stainless steel-TiB2 coatings were submitted to the ASTM G65-B abrasion test and the volume loss was measured with an optical profilometer. As expected, the volume loss decreases and the proportion of TiB2 increases. However, large differences in volume loss between coatings that contain about the same volumetric proportion of hard phases cannot be explained by a linear reationship. The inverse rule of mixing was proposed. This inverse rule of mixing was found particularly useful for determining the influence of additives. Tin, added in the core as a fugitive liquid transfer agent, was found to improve the wear resistance of coatings. These advanced arc sprayed stainless steel-TiB2 coatings can be favorably compared with coatings obtained by arc spraying commercially available solid and core wires.
