Development and Applications of Advanced SiC/(W, Ti)C Ceramic Sand Blasting Nozzle
|Course||Mechanical Manufacturing and Automation|
|Keywords||sandblasting nozzle erosion wear ceramic materials wear mechanisms SiC/(W,Ti)C ceramic|
Based on the requirements of sandblasting nozzles, advanced SiC/（W,Ti）C ceramic nozzles have been successfully developed. Extensive researches were carried out on its composition design, mechanical properties and microstrucrure. The application of gas-solid two phase theory, computer simulation of sandblasting process was discussed. Sandblasting experiments were carried out, and then the wear mechanism was studied.SiC/（W,Ti）C ceramic composites with different content of solid-solution （W,Ti）C were produced by hot pressing. The optimized hot-pressing parameters for SiC/（W,Ti）C were obtained for different volume content of （W,Ti）C. Results showed that the optimum sintering temperature is 1900℃, the hot-pressing pressure 30MPa, and the holding time 50min; The optimum volume content of （W,Ti）C is 70%. Under the optimum conditions, the Vickers hardness of this material is 25.944GPa, flexural strength 631MPa, and fracture toughness 4.38 MPa.m1/2.The flexure strength and hardness of SiC/（W,Ti）C ceramic composites continuously increased with the increase of （W,Ti）C content, while the fracture toughness decreased with the increase of （W,Ti）C content. There are a lot of obvious pores located at the pure SiC ceramic material, and the fracture model is transgranular fracture. While there are almost no pores observed in the SiC/（W,Ti）C ceramic material, in addition to, each phase distributed uniformly, and the primary fracture mechanism is combination of intergranular and transgranular.The results of velocity calculation and computer simulation of different structural sandblasting nozzles showed that calculation results have a good agreement with that of the simulations, and the movements of the particles in the nozzle are nearly symmetrical.