Coatings, composition, and method related to non-spalling low density hardface coatings

摘要

A composite body that is spall resistant and comprises a substantially discontinuous cermet phase in a substantially continuous metal rich matrix phase. The composite body is typically bonded to a substrate to form a hardfacing on the substrate. The composite body exhibits ductile phase toughening with a strain to failure of at least about 2 percent, a modulus of elasticity of less than about 46 million pounds per square inch, and a density of less than about 7 grams per cubic centimeter. The metal rich matrix phase between the ceramic rich regions in the composite body has an average minimum span of about 0.5 to 8 microns to allow ductility in the composite body. The composite body has a Vicker's hardness number of greater than approximately 650. The discontinuous cermet phase is in the form of ceramic rich regions embedded within the composite body, and it includes ceramic particles and a cermet binder. The ceramic particles having a Moh's hardness of at least approximately 7.5, a modulus of elasticity of less than approximately 46 million pounds per square inch, and an average particle size of from about 0.1 to 10 microns. The ceramic rich regions exhibit high hardness as compared with the matrix phase.