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

Abstract

A novel process of immersion fluid chemical mechanical polishing (CMP) is proposed to replace the traditional manual polishing and the mechanical polishing for integral impeller.Using the FLUENT software to simulate the force state on the integral impeller surface and the fluid motion trajectory during the polishing process, in order to determine the optimal polishing process , and to reveal the formation mechanism of the high-quality integral impeller surface. The immersion fluid CMP process experiment was carried out on the integral impeller with the developed CMP slurry containing phosphoric acid (H3PO4), hydrogen peroxide (H2O2), citric acid (CA), silicon carbide (SiC) and deionized water. After 2.5 hours of CMP, the surface roughness decreased from Ra 1.651 μm to Ra 0.658 μm, the polished surface is smooth and without tool marks. X-ray photoelectron spectroscopy (XPS) and infrared (IR) were used to reveal the polishing mechanism of the oxidation, dissolution, removal and complex precipitates on the surface of the integral impeller. This research provides a novel process for the precision machining of other complex structural parts similar to the integral impeller, which has the characteristics of simple polishing process, high efficiency and good polishing effect.