Laser Cladding of Paste Bound Hardfacing Alloys

Abstract

A new technique of laser cladding by a one step process, using paste bound hardfacing alloys, is presented. This process offers the possibility of exact positioning of the hardfacing alloy relative to the laser beam and thus close control of melting conditions. The possibility of prealloying the added hardfacing material with further elements (metals or metalloids) or with hard particles (e.g. carbides) is a further potential advantage. The process is introduced and examples of carbide/hard alloy claddings are given. Results of wear tests on Co–Cr–W–B–Si and Co–Ni–Cr–W–B–Si hardfacings produced by this method are reported. Compared with plasma sprayed hardfacings of the same composition, the laser clad paste bound materials produce coatings with improved wear resistance, provided dilution is kept low.