喷丸强度对 DD6 单晶高温合金表面完整性的影响

The service life of single crystal turbine blades, which serve as pivotal components in aero-engines, is intricately tied to their surface integrity. To fulfill performance standards, these blades typically undergo shot peening to meet for reinforcement. This study meticulously examines the impact of surface morphology and various surface integrity indicators -including roughness, near-surface microstructure, hardness, and residual stress -on DD6 single-crystal superalloy before and after undergoing shot peening treatments of varying intensities (0.15, 0.2 mmA, and 0.25 mmA). Utilizing a surface profilometer, scanning electron microscope, microhardness tester, and stress tester, we comprehensively analyze these factors. The results show that shot peening diminishes the original machining marks on the DD6 superalloy’s surface, with surface roughness escalating from 0.507 μm at 0.15 mmA to 0.883 μm at 0.25 mmA. A gradient plastic severe deformation layer emerges near the surface, its depth progressively increasing from 45 μm at 0.15 mmA to 98 μm at 0.25 mmA. Furthermore, the surface hardness value rises steadily, from 490HV in the original specimen to 738HV at 0.25 mmA, with the hardened layer’s depth also augmenting, from 50 μm initially to 260 μm at 0.25 mmA. Notably, the alloy attains its peak residual compressive stress of approximately -821.2 MPa on the surface when subjected to a blasting intensity of 0.2 mmA.