316L APS Al2O3-TiO2 system HVOF History of engineering & technology NiCr 80/20 S-phase Vickers microhardness ablation resistance additive manufacturing amorphous axial feeding bovine serum solution burner rig test carbon/carbon (C/C) composites chromium carbide coating design cold spray copper corrosion potential corrosion rate corrosion-wear performance dense structure double-layered TBC dynamic impact test expanded austenite flame spraying gadolinium zirconate gas nitriding hardening