摘要
研究了热压碳化硼在 973～ 12 73K的氧化行为及其对摩擦性能的影响 .氧化试样用X射线衍射分析其成分 ,用电子显微镜观察其微观形貌 .结果表明 ,氧化试样表面生成一层薄而透明的B2 O3液膜 .由于B2 O3与B4C材料的热膨胀系数相差甚远 ,因而冷却时发生龟裂 .B2 O3继而与空气中的水蒸汽发生反应 ,生成白色的H3BO3.H3BO3是一种固体润滑剂 ,当其出现于碳化硼摩擦副表面 ,可将摩擦系数由未经氧化处理的B4C/B4C摩擦副的 0 .2 5～ 0 .3 5降至 0 .0 5左右 .但氧化温度达 12 73K时 ,由于表面氧化腐蚀较严重 ,可能造成表面颗粒剥落 ,不利于降低摩擦系数 .
The oxidation behavior under 973-1273 K and the effect of oxidation on the room-temperature tribological properties of hot-pressed boron carbide ceramics were investigated. Oxidized samples were studied by X-ray diffractometer and scanning electron microscopy. It is demonstrated that the oxidation results in the formation of a thin transparent B2O3 film, and the oxide film is severely cracked during cooling due to the thermal expansion mismatch between the oxide film and the B4C substrate. B2O3 reacts with moisture in the air to form the boric acid, which is a kind of solid lubricant. The sliding friction coefficient of oxidized B4C/B4C friction pair is about 0.05-0.08, compared to 0.25-0.35 of the as-received B4C/B4C friction pair. When the temperature is up to 1274 K, a significant increase in friction coefficient is observed, as the friction interface is roughened by severe etching of grain boundaries.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2001年第1期44-48,共5页
Journal of The Chinese Ceramic Society
基金
国家有色工业局资助项目!(98-A2 8-11)
