Residual Stresses Evaluation in Tungsten Carbide Cobalt Coating from HVOF Process Using XRD Method

Residual stresses, that are inherent in thermal spray coatings as in tungsten carbide cobalt thermal coatings, can be useful or damaging for efficiency and life of specimen relate to their state. The present investigation has been done in order to determine the residual stresses through thickness in WC-12Co thermal spray coating from HVOF Process. These stresses were determined in surface of coating and through the thickness in 50, 150, 230 and 300 µm depths. Residual stresses were obtained tensile in 50 µm depth and compressive for surface of coating and other depths. It was observed that by approaching to the interface, further 50 µm, the magnitudes of stresses increase because the peening and thermal mismatch stresses dominant the quenching stresses. The average residual stress through coating thickness was calculated -157.1 MPa and compressive that is useful for the efficiency of specimen.