Study On Chemical Mechanical Polishing Of Agate In Central Asia

The search for new processing techniques and solutions for the creation of modern art products is usually associated with the use of new materials and improvements in their processing methods,which help to expand the composition of the art form with a variety of colors and textures.Agate is named for its beautiful ribbon pattern,and the culture of using agate for decorative and artistic products has a long history,even to modern times,when agate is often used for a variety of crafts.Agate is also loved by the people of Central Asia and has great historical and cultural significance.At present,the polishing method of agate is still based on the traditional method,such as the rigid grinding effect of abrasive and agate,but the processing environment is poor,the processing efficiency is low,and the labor cost is high.Therefore,the improvement of polishing methods to improve the quality and efficiency of agate polishing,combined with advanced polishing methods,can improve the application field and grade of agate.Therefore,in this project,based on the chemical composition of Central Asian agate,we studied the polishing fluid that can realize chemical mechanical polishing of this kind of agate by selecting appropriate abrasives and polishing fluid components,and built a polishing platform on an industrial robot to carry out polishing process experiments,and obtained a high gloss agate polished surface.The main research contents and achievements of this paper are as follows:(1)To chemical mechanical polishing solution as the research direction of agate,from agate mineral composition analysis,to choose chemical reagent with precise matching the appropriate polishing liquid,research through chemical reaction mechanism of oxide film,which has more smooth agate machining efficiency and surface gloss.It is mainly through the control of abrasive type,particle size,dispersion and p H value,as well as polishing pressure,speed and time variables.Abrasives are mainly diamond W5 and W3.5 micron.Three dispersants,sodium dodecyl sulfate(SDS),fatty alcohol polyoxyethylene ether(AEO)and cetyltrimethylammonium ammonium bromide(CTAB),were used to prepare the polishing solution.SDS was anionic dispersant,CTAB was cationic dispersant and AEO was non-ionic dispersant.SDS and CTAB were mixed with AEO respectively.PH regulator is sodium hydroxide(Na OH)and hydrochloric acid(HCl),the rest of the composition is oxidizer and deionized water.Firstly,uniform and stable diamond polishing suspension was prepared.The optimum concentration and p H value of mixing SDS and AEO or CTAB and AEO were determined by particle size,particle size distribution and Zeta potential.(2)In the process of chemical mechanical polishing,rough polishing and fine polishing were studied by orthogonal experiment respectively.Five factors and three levels were designed for the orthogonal experiment of rough polishing and fine polishing,and L18(3~7)orthogonal table was adopted.Among them,five factors were polishing pressure,polishing speed,moving speed,polishing time and oxidizer mass fraction.The most influential factors on surface roughness were obtained.Finally,based on the experimental results,the mechanism of chemical reagent in polishing solution was analyzed.After polishing solution with suitable proportion to onyx has good corrosion resistance,a layer of silicate and a small amount of sialic acid salt oxide film,and then under the action of diamond grits is removed well and so coarse after polishing surface roughness Ra agate fell to less than 50 nm,agate after polishing and fine surface roughness Ra fell to less than 20 nm,this agate can be proved to be of high quality by chemical mechanical polishing with suitable polishing fluid.