High-power laser cladding Stellite 6+WC with various volume rates

Laser cladding of Stellite+WC with WC volume percentages of 0%. 9%, 18%, 27%, 36%, 45%, 54%, 72%, and 100% was investigated by dual powder feeding. The results demonstrated that no cracking happened until the WC volume percentage was over 18%. The average hardness and cracking rate increased while the height/width rate decreased with increased WC volume percentage. The microstructure evolution can be divided into two domains. The first domain is from 0% to 36% WC, in which the added WC was completely melted and dissolved into the melt pool and the resolidified structure dominated by Co-rich dendrites and interdendrite eutectic containing 9.7 and 21 wt % W, respectively. The second domain is for the WC volume percentage from 45% to 100%, in which most of the WC was melted, and the microstructure was dominated by the matrix and the various faceted dendrites. The dissolution of W into the matrix was limited to a maximum of about 26 wt % and reached 64.6 wt % in the faceted dendrites. (C) 2001 Laser Institute of America.