The deposition of overlay coatings by welding or thermal
spray techniques is frequently employed (either during maintenance
or in the manufacture of new components) in a wide
range of industries [1,2] to improve the wear resistance of surfaces
in contact. In the sugarcane industry hardfacing is carried
out on grey cast iron mill rollers to reduce wear, to permit the
use of higher extraction loads and to aid the movement of the
crushed cane through the rollers [3]. Fig. 1 shows the schematic
arrangement of a typical cane mill that is used to extract the
juice from the sugarcane. The cane mill essentially consists of
three large horizontal roller shells that are shrunk onto a steel
shaft and arranged in the form of an isosceles triangle. The sugarcane,
which is cut and shredded, is passed through the rotating
rollers to extract the cane juice. The rollers are machined with a
series of V-shaped grooves around the circumference to improve
gripping (and thus transport) of the sugarcane through the mill.