Ultra-smoothness Grinding Mechanism of Fine Ceramics with Metal Bonded #140 Diamond Wheel

研究目的是建立大颗粒金刚石砂轮磨削细陶瓷的高去除超光滑磨削技术。本文首先以碳化硅陶瓷为材料，对粗颗粒金刚石砂轮超光滑磨削机理进行了实验和理论研究。实验是在数控平面磨床上进行的。所用金刚石砂轮的结合剂、浓度和粒度分别为金属100和#140。在此基础上，从理论上和实验上讨论了横向磨削能达到的极限光滑度的存在。在此基础上，提出了一种新的超光滑磨削方法，并确定该方法适用于超光滑表面的精加工。(1)采用#140金刚石砂轮进行超光滑磨削的碳化硅陶瓷表面粗糙度可达到10 nm(Ry)或2 nm(Ra)以下。(2)氮化硅陶瓷和碳化硅陶瓷的表面粗糙度略低于碳化硅陶瓷，但也接近超光滑表面。(3)未磨细陶瓷的硬质合金表面粗糙度可达30 nm(Ry)或4 nm(Ra)以下。

The research is done for the aims of building the high removal ultra-smoothness grinding technique of fine ceramics with coarse grain size diamond wheel. In the present research, first of all, by using silicon carbide ceramic, the mechanism of ultra-smoothness grinding with coarse grain diamond wheel is investigated experimentally and theoretically. The experiments are carried out with NC surface grinder. The bond, concentration and grain size of diamond wheel used are metal, 100 and #140, respectively. On the basis of the result, the existing of limiting smoothness, which can attain in traverse grinding is discussed theoretically and presented experimentally. Furthermore the newly devised ultra-smoothness grinding method is proposed and ascertained to be useful for finishing to near the ultra-smoothness surface.The main conclusions obtained using the new ultra-smoothness grinding method are as follows;(1) The surface roughness of silicon carbide ceramic formed by the ultra-smoothness grinding method using #140 diamond wheel is found to attain below 10nm(Ry) or 2nm(Ra).(2) The surface roughness of silicon nitride ceramic and alumina-titanium carbide ceramic is somewhat worse than silicon carbide ceramic though it attains to near the ultra-smoothness surface too.(3) In the cemented carbide without fine ceramics, the surface roughness attains below 30nm(Ry) or 4nm(Ra).