Influence of binder metals on the adhesive strength and the surface hardness in Fe-W alloy films electrodeposited on the high-speed steel

In order to improve the cutting ability of drills or endmills, Fe-W alloy e lectroplating was used to increase the surface hardness of the machine tool s. Furthermore, in order to increase the adhesive strength between the coat ed Fe-W alloy films and the high-speed steel substrate, Fe, Co and Cu were used as adhesives. Adhesive After annealing at 550 degrees C, the critical load at which the films pull out was Increased by the use or the adhesives. The order of increasing adhesive ability was Cu, Fe, Co and binder-less. O n the other hand, the surface hardness measured by dynamic hardness tester showed Co to be best, followed by Fe, binder-less, then Cu. This suggests t hat Fe is thought to be the most suitable for the binder metal. Cross-secti onal analysis by ESCA showed an extensive diffusion of Cu, Fe, and Co into the Fe-W alloy film and the high-speed steel.