Joining Of Zro₂ Ceramics By Microwave Sintering With Sic

This work was concerned on microwave joining of ZrO₂ ceramic process. Due to the different microwave absorption properties of SiC and its oxide (SiO2), and SiC would be oxidated to SiO2 at elevated temperature, interlayer containing SiC poder were designed. The zirconia ceramics were successfully joined together by microwave heating.The Num.C prescription was chosen to conduct the microwave joining experiment on a series of basic experiments, in which 55wt% SiC was contained. The joining mechanism was analyzed based on experimental results. It was showed that a microwave power increase rate as 1kW/20min could lead to a best joining effect. It was supposed that a suitable expanding and forming of SiO2 by SiC oxiding might occur, a main phase resulted by reaction of SiC oxide, migh joining quality. It was supposed that a volum expanding and forming of SiO2 by SiC oxidint promote the interfacial contacts by mass transfer duo to its sticky flow at elevated temperature. Based on tests concerning both interlayer thickness and joining pressure, it was showed that the best joining effect was realized with conditions of tiny pressure and thinner thickness,that is, the interlayer contains 25wt% solid content. The experimental results indicate that:The main mechanism of microwave joining is elements diffusion in the process of microwave joining process.ZrO₂ ceramic was effective joined using SiC-Al2O3 as interlayer.In the system of ZrO₂-SiC, a little of SiC would resulted the joining temperature too low to promote the formation of joint. On the contrary, too much SiC would produce high temperature and much of pores in the interlayer to promote joining.The lower microwave power can not make the interlayer achieve the joining temperature. At the same time, the much higher microwave power will make the interfaces melting.Pressure promotes the formation of joint. The exist of pressure on the interface effective control the expand of the interlayer,eliminate the pores in the interlayer and improve the joint performances.