HARDFACING USING SUPERSONIC LASER DEPOSTION OF STELLITE-6

摘要

The capability of manufacturing coatings is of centralrnimportance in engineering design. Many componentsrnrequire nowadays the application of additional layers,rnto enhance mechanical properties and protect againstrnhostile environments. Supersonic Laser Depositionrn(SLD) is a novel coating method, based upon ColdrnSpray (CS) principles. In this technique therndeposition velocities can be significantly lower thanrnthose required for effective bonding in CSrnapplications. The addition of laser heat energyrnpermits a change in the thermodynamic experience ofrnimpacting particles, thereby offering a greaterrnopportunity for metallurgical bonding at lowerrnvelocities compared to the CS process technology.rnThe work reported in this paper demonstrates thernability of the SLD process to deliver hard facingrnmaterials to engineering surfaces. Stellite-6 has beenrndeposited on low carbon steel tubes over a range ofrnprocess parameters, determining the appropriaterntarget power and traverse speeds for coatingrndeposition. Coating properties and parameters werernexamined to determine the main properties, microstructurernand processing cost. Their morphology wasrnstudied through optical microscopy, SEM and X-RayrnDiffraction. The results have shown that SLD isrncapable of depositing Stellite-6, with enhancedrnproperties compared to laser clad counterparts.