【摘要】 用热压烧结法制备了Si₃N₄/TiC和Al₂O₃/TiC陶瓷水煤浆喷嘴。测量了喷嘴的磨损质量损失,用扫描电子显微镜观察了喷嘴磨损后的表面形貌,研究了其磨损特性。结果表明:陶瓷水煤浆喷嘴材料的硬度和断裂韧性对其热冲蚀磨损有重要影响。在相同条件下,硬度较高的Al₂O₃/TiC陶瓷喷嘴的磨损率较低,而断裂韧性较高的Si₃N₄/TiC陶瓷喷嘴的热冲击损伤较小。陶瓷喷嘴磨损表面因区域不同而显示不同的特征,Si₃N₄/TiC陶瓷喷嘴的损坏机理主要表现为塑性变形、脆性断裂、研磨损伤、热裂纹和热崩。更多还原

【Abstract】 Si₃N₄/TiC and Al₂O₃/TiC ceramic nozzles were fabricated by the hot-pressing technique.Their wear characteristics were investigated in coal-water-slurry （CWS） industrial boilers.The mass loss of the worn nozzles was measured.The eroded bore surface morphologies of the nozzles were examined with scanning electron microscopy.The results show that the hardness and fracture toughness of ceramic CWS nozzle materials play an important role with respect to the thermal erosive wear resistance of ceramic nozzles.The Al₂O₃/TiC ceramic nozzles with high hardness exhibit lower wear rates,while Si₃N₄/TiC ceramic nozzles with high frac- ture toughness show better performance in decreasing thermal shock damage.Analysis of the eroded bore surfaces of ceramic nozzles demonstrates that the wear characteristics of nozzles vary with the different nozzle zones.The failure mechanisms of Si₃N₄/TiC ceramic nozzles are mainly shown as plastic transformation,brittle fracture,polishing,thermal cracking and collapsing.更多还原