关键词: 高温合金, NiCrAlY涂层, 单晶刚玉砂轮, 正交优化, 表面完整性, 精密磨削

Abstract: To address critical challenges in synchronous grinding of GH4169 superalloy substrates with NiCrAlY thermal barrier coatings—including excessive dimensional deviation,grinding cracks,and coating delamination—a precision grinding process using Single-Crystal Alumina (SCA) wheels was developed. Comparative analysis revealed that SCA wheels can significantly suppress edge chipping compared to white alumina wheels. Through a three-factor,three-level orthogonal experiment,the significance order of key process parameters affecting dimensional accuracy Δ and surface roughness Ra was determined as wheel feed speed > wheel rotational speed > grinding depth and wheel rotational speed > wheel feed speed > grinding depth. The optimized process parameter combination was wheel feed speed of 8 mm/min,wheel rotational speed of 2 500 r/min,grinding depth of 3 μm. Post-optimization results demonstrate 42.9 % improvement in dimensional accuracy (Δ=1.2 μm),46.3 % reduction in surface roughness (Ra=0.2 μm),elimination of grinding cracks and coating delamination (validated by microscopic inspection). Batch production verification confirmed that metallurgical structure was compliance with HB 6702 standard,product qualification rate was increased to 99.2 %,providing a high-reliability grinding solution for aero-engine high-temperature component remanufacturing.

Key words: superalloy, NiCrAlY coating, Single-Crystal Alumina(SCA) wheel, orthogonal optimization, surface integrity, precision grinding