High-velocity air fuel (HVAF) spraying was selected for spray trials of a Cr3C2-NiCr powder. To determine the effect of spray parameters on coating characteristics, particularly porosity and phase degradation, a statistical design of experiments was implemented. A wide range of statistical designs have been applied to the optimization of thermal spray coatings with a great deal of success. In this instance, a lack of prior knowledge and the need to assess many process-variable interactions efficiently led to the selection of a two-level full factorial design. High and low settings for each variable, including spray distance, traverse speed, and powder feedrate, were chosen based on the ranges typically used to spray similar materials. The resulting coatings were assessed for microhardness, porosity, residual stress, deposition efficiency, and phase transformation, after which several follow-up runs were conducted to explore trends brought to light by the initial factorial design.

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