Design Theory And Application Of Gradient Ceramic Nozzles

The idea of functionally gradient material (FGM) theory was used to design of ceramic nozzle based on the erosion wear behaviors of the ceramic nozzles and on the outstanding properties of FGMs. The purpose is to reduce the tensile stress at the entry region of the nozzle during sand blasting processes. The design theory and methods of gradient ceramic nozzle were proposed. SiC/(W,Ti)C gradient ceramic nozzles with high performance and long life have been successfully developed by hot pressing. The erosion wear mechanisms of these gradient ceramic nozzles were investigated.The velocity of the abrasives particles and the stress inside the ceramic nozzle were analyzed. The mechanics mechanisms of the erosion wear of the ceramic nozzle was presented. The design theory and methods of gradient ceramic nozzle were proposed based on the erosion wear behavior and stress status of the ceramic nozzles. The physical, composition distribution, and property parameter models of gradient ceramic nozzle were established.The aim of the design for gradient ceramic nozzle was proposed. The ultimate content of SiC and (W,Ti)C inside SiC/(W,Ti)C gradient nozzle materials were determined based on the physical and chemical compatibility analysis. Finite element models for residual stress analysis were established, and the residual stress statuses inside GN-1 and GN-2 gradient nozzle were analyzed. Results showed that compressive residual stresses were appeared both at the entry zone and at the exit area of the gradient nozzle. The optimum parameters of the component distribution exponent, the layer thickness, and the volume difference of SiC in various gradient layers of the SiC/(W,Ti)C...