C/Al2O3复合材料的固体粒子冲蚀行为与磨擦磨损性能研究

Solid Particle Erosion Behavior and Friction and Wear Properties of C/Al2O3 Composites

摘要:

以溶胶浸渍热处理技术路线制备的碳纤维布叠层缝合预制件增强Al₂O₃(C/Al₂O₃)复合材料为对象,以刚玉粉为介质,研究了复合材料的固体粒子冲蚀行为,按照GB5763-2008规定的条件研究了复合材料的磨擦磨损性能。室温下,复合材料冲蚀率随着冲击角度与送粉量的增大而增加；温度升高,由于机械冲击和热冲击的双重作用,冲蚀率显著变大。在GB5763-2008规定的条件下,C/Al₂O₃复合材料具有稳定的摩擦系数和很低的磨损率。结合微观形貌分析,探讨了复合材料的冲蚀与磨损机理。得益于连续碳纤维的补强增韧作用,即使基体致密度低于单体Al2O3陶瓷，C/Al₂O₃复合材料在冲蚀和磨损时不会发生脆性断裂,使用安全性优于单体Al₂O₃陶瓷。

Abstract:

Alumina matrix composites reinforced by carbon fiber cloth preform with a lamination and stitching structure (C/Al₂O₃) and fabricated by sol infiltration and heat treatment route were selected as raw materials in this paper. The solid particle erosion behavior of C/Al₂O₃ composites was investigated using corundum powders as medium, and the friction and wear properties were studied according to national standard GB5763-2008. At room temperature, erosion rate is augmented with increasing impact angle and feeding rate of corundum powders. The remarkably enhanced erosion rates are observed at high temperatures due to the combination of mechanical impact and thermal shock. C/Al₂O₃ composites exhibit stable friction factor and very low wear rate under the conditions regulated by national standard GB5763-2008. The erosion and wear mechanisms are discussed based on the evolution of microstructure. Profiting from the reinforcing and toughening mechanism of continuous carbon fiber, C/Al2O3 composites present non-catastrophic fracture behavior and better security in service than monolithic Al2O3 ceramics even if the matrix density of C/Al2O3 composites was inferior to monolithic Al2O3 ceramics.