Exploring the impact of cryogenic treatment on detonation spray coated M2 high speed steel

An Al₂O₃–13% TiO₂ coating was applied to M2 high-speed steel using the d-gun process. The surface properties were compared between uncoated samples, coated samples before cryogenic treatment (CBCT), and coated samples after cryogenic treatment (CACT). The mean particle size was ~17.07 μm, with average coating thicknesses of 212 μm for CBCT and 196 μm for CACT. CACT exhibited 3.19% and 24.65% higher microhardness than CBCT and uncoated samples, respectively. All samples exhibited hydrophilic wettability, with CBCT showing 59.41% and 67.43% higher Ra values, along with 56.03% and 59.70% higher Rz values than CACT and uncoated samples. CBCT also exhibited 32.96% and 98.14% higher porosity than CACT and uncoated samples. CACT showed reduced abrasion loss by 54.05% and 36.25% compared to CBCT and uncoated samples. CBCT has better corrosion resistance of 90.25% and 95.89% than CACT and uncoated samples. The Raman shift revealed increased particle size formation in CACT than other samples.