蓝宝石磨削表面微观形貌特征研究

Research on Sapphire Surface Microstructure Processed by Diamond Grinding Wheel

蓝宝石单晶因其耐高温、耐腐蚀及高硬度,广泛应用于兵器、航空与航天等领域。蓝宝石磨削加工表面形貌特征对其后续加工及使用性能有重要影响。为分析不同加工因素下的蓝宝石表面形貌特征,进行了不同结合剂、不同粒度的金刚石砂轮蓝宝石磨削试验,利用白光干涉仪对工件表面粗糙度进行了检测,利用扫描电子显微镜对表面微观形貌特征进行了分析。试验结果表明,当磨削深度处于亚微米级尺度内时,树脂结合剂砂轮加工表面质量优于金属结合剂砂轮加工表面质量;减小砂轮磨粒直径有助于提高加工表面质量;较高的砂轮磨削速度不利于获得表面粗糙度值小的加工表面;在脆性断裂去除模式下,蓝宝石表层材料剥落易形成不规则凹坑,光滑台阶状断裂面的形成与蓝宝石单晶解理有关,并且磨削深度越大,加工表面解理断裂特征越显著。

With characteristics of high-temperature resistance,corrosion resistance and high hardness,sapphire is widely used in weapon communication industry,aviation and aerospace field.The ground sapphire surface topography has a great influence on the subsequent processing and use.To study the effect of various processing factors on the surface quality of sapphire,the grinding experiments of different particle sizes,different bonds were designed.The surface roughness and microstructure feature of ground sapphire was detected by white light interferometer and scanning electron microscope,respectively.Experimental results show that when the grinding depth in the sub-micron range,compared with metal bond grinding wheel,resin bond grinding wheel is conducive to higher quality sapphire surface.Reducing the grain diameter is helpful to improve the quality of processing surface.The higher speed of grinding wheel is not conducive to obtain sapphire surface with lower roughness.Ground sapphire surface form irregular pits easily,and smooth step pits associated with sapphire single crystal cleavage fracture.With the increase of grinding depth,sapphire surface cleavage fracture feature is more significant.