A novel high-quality and high-efficiency immersion fluid chemical mechanical polishing process for integral impellers

A novel immersion fluid chemical mechanical polishing (CMP) process is proposed to achieve high-quality and high-efficiency polishing of integral impellers. We used FLUENT software to simulate the force state on the integral impeller surface and the fluid motion trajectory during the polishing process under different conditions, aiming to reveal the formation mechanism of the high-quality blade surface. The determined optimal polishing process solution assumed connecting the large end face and rotating clockwise around the integral impeller center. The surface roughness (Ra) of the integral impeller was reduced from 1.651 to 0.658 mu m, yielding a smooth surface after 2.5 h of the immersion fluid CMP process. X-ray photoelectron spectroscopy (XPS) and infrared (IR) spectrometry were used to reveal the polishing mechanism of the metal M (Cr/Fe) oxidation, oxide M2Ox dissolution and removal, and complexation of metal ion Mx+ with citric acid on the surface of the integral impeller. This research provides a novel, simple, and highly efficient approach for the precision machining of complex structural parts similar to integral impellers, yielding a good polishing effect.