Optimizing HVOF spray process parameters to improve adhesion of WC-12Co coatings

Abstract

Adhesion of heat-treated coatings has significantly role on the longevity of components
that works in wear - resistance conditions. Beside the factors related to material
properties, the spraying parameters greatly affect the adhesion of the coating to the
base metal. This paper aims to find optimal parameters of HVOF (High velocity oxy
fuel) process including spray distance (A), injection distance (B), rate of combustion
mixture between Oxygen and Propane (C) to the adhesion of WC-12Co coating on
16Mn steel by Taguchi method. ANOVA (Analysis of variance) is applied to evaluate
the effect of the spray parameters on the adhesion. Results indicate that with A = 32
g/min, B = 0.275 m, C = 5, the adhesion can be achieved highest value and the order of
influence of the factors on adhesion is B > C > A. The experimental result is then
compared to optimal results and the error is only 0.5%. Hence, one can say that the
optimal results are reliable. In addition, a mathematical regression which shows the
relationship between the adhesion and spray parameters is found; it allows to predict
adhesion values based on spray parameters.