Experimental design and characterization based optimization of detonation sprayed fused alumina zirconia deposition

Detonation gun (D-gun) spraying is particularly useful for coating metals, non-metals such as carbides, ceramic and ceramic composite materials. Unlike the plasma spraying process, which is associated with defects such as porosity and un-melted particles, detonation spraying process facilitates, denser deposition with minimum defects. However an optimum selection of process parameters is a major issue in detonation spraying for economic and efficient utilization. This paper presents a study on the influence of four basic process parameters (Fuel: Oxygen ratio, Carrier gas flow rate, Detonation frequency and Stand-off distance) on performance indicators such as thickness (build-up), deposition rate, hardness and surface roughness features (Ra and Rt) of Alumina-Zirconia (AZ-23) composites. The optimum setting of coating parameters has been determined through analysis of signal to noise ratio (S/N ratio) using Taguchi factorial design method. The analysis of results indicates that Stand-off distance and Carrier gas flow rate have more significant effect on process indicators.