Study On Surface Roughness And Anti-Oxidation Corrosion For Al-Mg Alloy Chemical Mechanical Polishing

Al-Mg alloy was widely used in national defense, aviation, spaceflight and other fields because of its special physic properties and important application value. For such material used in these areas it needed to perform high precision machining with nearly no defects or impurities. High-precision, low roughness and no-damage surface can be obtained by using CMP technology. In this paper, CMP technology was expanded into processing of Al-Mg alloy.The surface of Al-Mg alloy was easily scratched by high pressure as the hardness is very low. Al was easily oxidized to generate a layer of oxide film, but Al-Mg alloy contains Mg, Fe, Ni and other metal impurities which made the oxide film ineffective, then the surface of Al-Mg alloy was easily to be corroded, which leaded the polishing of Al-Mg alloy difficult.This paper focused on analysis of the factors that accelerate the transfer rate of CMP to keep the role of mechanical action and chemical action balance to reduce the surface roughness.The main contents of this paper as following:(1) The Al-Mg alloy CMP mechanism was discussed which laid a basic theory for studying roughness of surface.(2) According to the particularity of Al-Mg alloy, non-oxidant polishing technology was proposed in this paper. From the point of reducing the surface roughness of Al-Mg alloy, the polishing liquid which is suitable for Al-Mg alloy was developed. The influence of pH value, pressure, flow rate, rotational speed on Al-Mg alloys surface state was analyzed through the experiment.(3) Analyzing of the corrosion theory of Al-Mg alloy, the method of temporary protection for the Al-Mg alloy surface is proposed, and achieved good results.(4) This paper focused on analysis of the factors that accelerate the transfer rate of CMP to keep the role of mechanical action and chemical action balance to reduce the surface roughness and achieve the effect of global glamorization.Such results can be benefit for the further study of Al-Mg alloy surface machining by using CMP technology.