Abstract: The Chemical Mechanical Polishing(CMP) technology was introduced into magnesium alloy surface ultra-precision process,silica sol,active agent,chelating agent,pH regulator was used to prepare polishing solution by vortex mixing.At the same time,the effect of pressure,rotation,flow rates of sully process and time on the polishing were analyzed by singer factor test.The experimental results showed that:the pressure is 0.06MPa,upper plate speed is 10r/min,lower plate speed is 50r/min,flow rates of slurry is 160mL/min,polishing time is 8min,the alloy surface morphology is good ;under optimum conditions after chemical mechanical polishing,the surface roughness Ra of the alloy can reach 10nm.

Key words: Chemical Mechanical Polishing(CMP), magnesium alloy, process parameters, surface roughness