Stellite 6 powders were deposited on low carbon steel using SLD (supersonic laser deposition) under optimized parameters. The structure, line scan of elements and porosity of coating were examined and analyzed using SEM (scanning electron microscope), OM (optical microscope) and XRD (X-ray diffraction). The adhesion strength between coating and substrate was tested by PAT-ADHESION/TENSILE and E900STM adhesive. The results showed the deposition characteristics of optimized coating with N2 at a pressure of 3.0 MPa, a temperature of 450 ℃ and a laser power of 1.5 kW were compared with those of Stellite 6 coating deposited by the HVOF (high velocity oxygen fuel).
LUO FangLupoi RoccoCockburn AndrewSparkes MartinO'neill WilliamYAO Jian-hua
The supersonic laser deposition(SLD)is a new fabrication process which combines the supersonic powder stream found in cold spray with laser heating of the deposition zone.Because of the instantaneity of particles impact,the deformation behaviors and the adhesion behaviors of particles impacted on the substrate by SLD cannot be well investigated through experiments.Therefore,a finite element model was developed to solve the problems above.Meanwhile,the heat effect of the substrate heated by laser was discussed.The effective plastic strain and the effective stress between the particle and substrate at different laser preheat temperatures were studied.The results show that laser depositing temperatures of 1 000 and 1 100℃ on substrate would be the optimized for the bonding of particles and substrate.In addition,the simulation results conformed to experimental results.
