用BYK180分散剂和稀土抛光粉配制抛光液,借助吸光度和沉降体积等指标研究了分散剂用量、pH、搅拌速率和时间等参数对稀土抛光液分散性能的影响。结果表明,随着BYK180用量、搅拌速率和搅拌时间的增加,抛光液的分散性先增加后降低。pH=6.8为此抛光液的等电点,在一定pH范围内,偏离等电点越远,抛光液吸光度越大,且碱性体系的吸光度略大于酸性体系。当抛光液酸性和碱性过强时,吸光度又变小。获得最佳分散效果抛光液的工艺参数为:BYK180用量0.75%,溶液pH=9.5,搅拌速率2000r/min,搅拌时间120min。
Polishing slurry was prepared from BYK180 dispersing agent and rare earth bearing polishing powder. The effect of parameters including dosage of BYK180, pH value, stirring speed and time on dis- persity of the polishing slurry was studied with the assistance of indexes of absorbance and sediment vol- ume. The results show that with the increase of BYK180 dosage, stirring speed and time, the dispersity of the polishing slurry rises at first and then declines, pH value of 6.8 is the isoelectric point of the polishing slurry. Within a certain range of pH value, the farther deviation from the isoelectrie point is, the larger absorbance of the polishing slurry is obtained, and the absorbance in basic system is slightly stronger than that in acid system. The absorbance starts to decline when the acidity or basicity of the polishing slurry is extremely strong. The optimal parameters for the dispersity of the polishing slurry include BYK180 dosage of 0.75%, pH value of 9.5, stirring speed of 2 000 r/min and stirring time of 120 min.