Experimental design and performance analysis of alumina coatings depositedby a detonation spray process

The increasing demands for high-quality coatings has made it inevitable tha t the surface coating industry would put more effort into precisely control ling the coating process. Statistical design of experiments is an effective method for finding the optimum spray parameters to enhance thermal spray c oating properties, In the present investigation, an attempt is made to prod uce high-quality alumina (Al2O3) coatings by optimizing the detonation spra y process parameters following a (L16-2(4)) factorial design approach. The process parameters that were varied include the fuel ratio, carrier gas flo w rate, frequency of detonations and spray distance. The coating characteri stics were quantified with respect to roughness, hardness and porosity. The performance of the coatings was quantitively evaluated using erosion, abra sion and sliding wear testing. Through statistical analysis of the experime ntal results, performed by the ANOVA method, the significance of each proce ss parameter together with an optimal variable combination was obtained for the desired coating attributes, Confirmation experiments were conducted to verify the optimal spray parameter combination, which clearly showed the p ossibility of producing high-quality Al2O3 coatings.