Impact Temperature in Splat and Splat-Substrate Interface in HVOF Thermal Spraying
— An explicit axisymmetrical FE methodology is developed here to study the particle temperature arising in WC-Co particle on an AISI 1045 steel substrate. Parameters of constitutive Johnson-cook model were used for simulation. The results show that particle velocity and kinetic energy have important role in temperature arising of particles.
Potential of High Velocity Oxy Fuel Thermal Spraying in Turbine Shaft Repairing
In this paper, the application of thermal spray coatings in high speed shafts by a revolution up to 23000 RPM has been studied. The agglomerated WC-12Co powder was coated on gas compressor components using high velocity oxy fuel (HVOF) method and its microstructure and residual stress were evaluated. Two high speed shafts were coated using the experimental data and the results demonstrated an acceptable performance in the high cycles. The results have shown that the developed coating has 148±30 MPa using hole drilling method and 156-257 MPa compressive residual stresses in curvature method. Morphological and crystallographical studies were conducted using optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction respectively to evaluate the powder and coating characteristics. [M. Jalali Azizpour, S. Norouzi, E. Pipelzadeh, D.Sajedipour, H.Talebi, A.Ghamari, b.Aslani. Potential of High Velocity Oxy Fuel Thermal Spraying in Turbine Shaft Repairing. Journal of American Science 2011;7(10):69-73]. (ISSN: 1545-1003). http://www.americanscience.org. Keywords—Hole drilling, Residual stress, WC-12Co, Thermal spraying.
Modeling of temperature and residual stress fields resulting from impacting process of a molten Ni particle onto a flat substrate
Several effective numerical techniques, based on a finite element analysis, have been developed and computed independently. Results are presented describing the impacting process, and the subsequent temperature and residual stress fields of a molten nickel particle impacting onto a flat substrate. Problems of this type, especially the prediction of the thermal residual streses, are of major practical interest in thermal spray operations as a pioneering approach.