Ceramics in the processing of some matters needing attention

Zirconia ceramic is a kind of inorganic non-metallic material made by sintering at high temperature. It has the advantages of high temperature resistance, corrosion resistance, wear resistance and thermal shock resistance. In recent years, with the progress of ceramic toughening and strengthening technology and the development of machining methods, the application range of zirconia ceramics is expanding rapidly.

Among the processing methods of zirconia ceramics, the mechanical processing method has high efficiency, so it has been widely used in industry, especially the grinding, grinding and polishing with diamond wheel. Most of the other processing methods of zirconia ceramics are suitable for drilling, cutting or micromachining. When cutting, most of the diamond grinding wheel is used for grinding and cutting, and when drilling, ultrasonic processing, grinding or grinding are carried out according to different aperture respectively.

Although there are many processing methods for zirconia ceramics, the processing cost is high, the processing efficiency is low and the processing accuracy is poor. One of the main reasons for this is the very high hardness of ceramics. For the unburned or calcined zirconia ceramic body mainly by cutting machining rough machining, after sintering by grinding finishing.

According to the different conditions of zirconia ceramics, the sintered body can also be directly grinded without machining to achieve the design accuracy. In terms of processing, zirconia ceramics are almost similar to metal parts, but the processing margin for zirconia ceramics is much larger. In rough machining of unfired or calcined ceramics, it is easy to have problems of insufficient strength or surface machining defects, or because of insufficient loading card and other reasons, and can not obtain the required final machining shape. Due to the sintering can not maintain uniform shrinkage, in rough machining to make the size is not too close to the final size, so there is a large margin for finishing. For metalworking, the finishing allowance should be as few hundredths of a millimeter as possible if thermal deformation and heat-treated black skin are taken into account. For ceramic processing, finishing allowance needs to have a few millimeters or even more than ten millimeters. Large processing allowance, reduced productivity, increased production costs.

Another problem of zirconia ceramic processing is the cost of cutting tools. Large cutting processes need to use high-price sintered diamond and CBN tools. The finishing process is also dominated by diamond grinding wheels, so the cost of cutting tools is tens of times to hundreds of times higher than that of metal cutting tools. The strength of zirconia ceramics is sensitive to the processing conditions, and it is difficult to achieve high efficiency processing, so the processing cost of zirconia ceramics is much higher than that of ordinary materials.