The properties of free-form laser-consolidated Stellite 6 alloy

Free-form laser consolidation of Go-base Stellite 6 alloy has been investigated. The Stellite 6 components built up by the process are metallurgically sound, without cracks and porosity. The laser-consolidated (LC) Stellite 6 is harder, stronger and even more ductile than the respective material produced by either casting or the powder metallurgy method. The tensile strength of the material is about 1245-1360 MPa, which is about 50% higher than that of the cast or powder metallurgy Stellite 6. The hardness of the LC Stellite 6 is about Re 58-59, while only about Re 37-46 can be obtained for the same material through the casting or powder metallurgy method. The LC Stellite 6 shows substantially higher yield strength and slightly higher elongation than the cast or powder metallurgy Stellite 6. The excellent mechanical properties of the LC Stellite 6 can be attributed to its exceptionally fine columnar dendrite microstructure produced by the rapid solidification associated with the process. The material was examined in detail by optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) and Auger electron microscopy (AES). The electrochemical polarization curve of the LC Stellite 6 in 3.5% NaCl solution was also measured and compared with other materials.