B4C/(W,Ti)C陶瓷喷砂嘴冲蚀磨损机理研究

采用热压烧结工艺制备了B4C／(W，Ti)C陶瓷喷砂嘴；采用SiC、白刚玉和棕刚玉磨粒对所制备的喷砂嘴进行冲蚀试验，在应力分析基础上探讨了陶瓷喷砂嘴的冲蚀磨损机理，结果表明：B4C／(W，Ti)C陶瓷喷砂嘴的冲蚀率随着磨粒硬度和粒度的提高而增大；喷砂嘴入口磨损最严重，出口次之，而中间区域磨损相对较轻；相应的应力分析结果同试验结果相吻合；以棕刚玉作为冲蚀磨料时，B4C／(W，Ti)C陶瓷喷砂嘴主要呈现应力疲劳断裂冲蚀特征，而以白刚玉和SiC作为冲蚀磨料时，喷砂嘴入口处主要呈现脆性断裂冲蚀特征，中问区域则主要呈现应力疲劳断裂冲蚀特征。

Erosion Wear Mechanisms of B4C/(W,Ti)C Ceramic Nozzles

B_4C/(W,Ti)C ceramic nozzle was prepared by hot pressing. The erosion behaviors of the resulting ceramic nozzle abraded by SiC, white emery, and umber emery abrasives were investigated on a GS-6 sand blast machine. The erosion-wear mechanisms of the ceramic nozzle were discussed based on stress analysis at various locations of the nozzle using finite element method and morphology observation of the entry and middle of the nozzle using scanning electron microscopy. It was found that the erosion-wear behavior of the ceramic nozzle was closely related with the types and grit sizes of the abrasive particulates. Namely, the harder SiC abrasive led to a more severe erosion-wear of the nozzle, while the softer umber emery abrasive led to a minimized erosion mass loss of the tested nozzle. Moreover, the erosion-wear mass loss of the ceramic nozzle increased with increasing grit size of the same abrasive, which corresponded to the different stress levels, the same as that for different abrasives types. At the same time, the erosion-wear mechanisms of the ceramic nozzles also varied with the variation of the abrasive types and the grit size, and with the locations along the lateral direction of the nozzle as well. Therefore, the nozzle was dominated by brittle fracture at the entrance and by stress fatigue in the middle as it was eroded by SiC and white emery abrasives, while it was characterized by stress fatigue in the presence of the umber emery abrasives.