Ni-20Cr/hBN自润滑材料的高温氧化行为
来源期刊：中国有色金属学报2013年第2期
论文作者：王常川 王日初 彭超群 冯艳 韦小凤
文章页码：356 - 362
关键词：镍基自润滑复合材料；hBN；高温氧化；动力学
Key words：Ni-based self-lubricating composites; hBN; high temperature oxidation; kinetics
摘 要：采用粉末冶金法制备六方氮化硼(hBN)含量为8%、10%和12%(质量分数)的Ni-20Cr/hBN自润滑复合材料，研究其在600、700和800 ℃的高温氧化行为，绘制氧化动力学曲线，并利用XRD和SEM分析氧化层的成分和形貌。结果表明：Ni-20Cr/hBN复合材料在600 ℃氧化300 h后氧化反应不明显；在700和800 ℃氧化300 h后出现较明显的氧化产物，主要有Cr2O3、NiCr2O4和CrBO3。氧化反应前100 h的氧化行为符合氧化增量动力学曲线，800 ℃的氧化抛物线速率常数比700 ℃的高一个数量级；而氧化100 h后，由于B2O3的熔融，试样质量保持不变或甚至呈下降趋势；在700 ℃下连续氧化膜基本形成，起到较好的保护作用，在800 ℃时氧化膜出现不同程度的腐蚀。
Abstract: The Ni-20Cr/hBN self-lubricating composites were prepared by powder metallurgy with hBN contents of 8%, 10% and 12% (mass fraction). Its oxidation behaviors were studied in air at 600, 700 and 800 ℃. The oxidation kinetics curves were gained, and the oxide compositions and morphologies were analyzed by XRD and SEM. The results show that the oxidation of Ni-20Cr/hBN composites oxidized at 600 ℃ for 300 h is not obvious. The oxide products consist of Cr2O3, NiCr2O4 and CrBO3 at 700 and 800 ℃ for 300 h. The kinetic curves of the composites obey the parabolic rate law at the beginning oxidation of 100 h, and the oxidation parabolic rate at 800 ℃ is a magnitude higher than that at 700 ℃. Meanwhile, the masses of Ni-20Cr/hBN composites become stable or even decrease after 100 h due to melt of B2O3. The oxide scales are complete and do well in protection at 700 ℃, while are corroded to some extend at 800 ℃.
王常川，王日初，彭超群，冯 艳，韦小凤
(中南大学 材料科学与工程学院，长沙 410083)
摘 要：采用粉末冶金法制备六方氮化硼(hBN)含量为8%、10%和12%(质量分数)的Ni-20Cr/hBN自润滑复合材料，研究其在600、700和800 ℃的高温氧化行为，绘制氧化动力学曲线，并利用XRD和SEM分析氧化层的成分和形貌。结果表明：Ni-20Cr/hBN复合材料在600 ℃氧化300 h后氧化反应不明显；在700和800 ℃氧化300 h后出现较明显的氧化产物，主要有Cr2O3、NiCr2O4和CrBO3。氧化反应前100 h的氧化行为符合氧化增量动力学曲线，800 ℃的氧化抛物线速率常数比700 ℃的高一个数量级；而氧化100 h后，由于B2O3的熔融，试样质量保持不变或甚至呈下降趋势；在700 ℃下连续氧化膜基本形成，起到较好的保护作用，在800 ℃时氧化膜出现不同程度的腐蚀。
关键词：镍基自润滑复合材料；hBN；高温氧化；动力学
WANG Chang-chuan, WANG Ri-chu, PENG Chao-qun, FENG Yan, WEI Xiao-feng
(School of Materials Science and Engineering, Central South University, Changsha 410083, China)
Abstract:The Ni-20Cr/hBN self-lubricating composites were prepared by powder metallurgy with hBN contents of 8%, 10% and 12% (mass fraction). Its oxidation behaviors were studied in air at 600, 700 and 800 ℃. The oxidation kinetics curves were gained, and the oxide compositions and morphologies were analyzed by XRD and SEM. The results show that the oxidation of Ni-20Cr/hBN composites oxidized at 600 ℃ for 300 h is not obvious. The oxide products consist of Cr2O3, NiCr2O4 and CrBO3 at 700 and 800 ℃ for 300 h. The kinetic curves of the composites obey the parabolic rate law at the beginning oxidation of 100 h, and the oxidation parabolic rate at 800 ℃ is a magnitude higher than that at 700 ℃. Meanwhile, the masses of Ni-20Cr/hBN composites become stable or even decrease after 100 h due to melt of B2O3. The oxide scales are complete and do well in protection at 700 ℃, while are corroded to some extend at 800 ℃.
Key words:Ni-based self-lubricating composites; hBN; high temperature oxidation; kinetics
