摘要
利用等离子体浸没离子注入与沉积(PIIID)复合强化技术,在AISI440C航空轴承钢表面合成了类金刚石碳(DLC)薄膜。Raman光谱分析揭示出所制备的DLC膜层主要是由金刚石键(sp3)和石墨键(sp2)组成的混合无定形碳膜,且sp3键含量大于10%。原子力显微镜(AFM)形貌表明,DLC膜层表面光滑,结构致密均匀,与基体结合良好。被处理薄膜试样在90%置信区间下的疲劳寿命L10,L50,特征疲劳寿命La和平均寿命较基体分别延长了10.1,4.2,3.5和3.6倍。ANSYS模拟结果显示,最大剪切应力出现在膜基结合处并且靠近膜层内部,最大值达到2150MPa。结合ANSYS模拟结果和扫描电镜(SEM)观察形貌分析发现,膜层内部存在的微观缺陷是滚动接触疲劳裂纹产生的诱因,循环载荷所形成的最大剪切应力和润滑油中污染颗粒的共同作用是疲劳磨坑最终形成的外在动力。建立了循环载荷条件下PIIIDDLC/AISI440C轴承接触疲劳破坏的5阶段物理模型。
Diamond-like carbon （DLC） films are synthesized by the plasma immersion ion implantation and deposition （PIIID） technique on the steel substrate surface of aerospace bearing AISI440C. Raman spectroscopy analysis indicates that the DLC consists of a mixture of amorphous and crystalline phases, with a variable ratio of sp^2/sp^3 carbon bonds in which the sp^3 bonds content is more than 10%. Atomic force microscope （AFM） reveals that the DLC film has extremely smooth surface, very high uniformity, and efficiency of space filling over large areas. The rolling contact fatigue （RCF） life results show that the maximum L10 ,L50 ,La and mean fatigue life L of the treated samples, at 90% confidence level, increase by 10.1, 4.2, 3.5, and 3.6 times respectively. The ANSYS simulation result exhibits that the maximum shear stress is about 2.15 GPa, which is generated in the substrate-film interface inside a certain depth in the film layer. Combined with the scanning electron microscope （SEM） morphology of DLC/AISI440C bearing fatigue pitches, a conclusion can be drawn that the micro-defects in the film interior induce the initiation of rolling contact fatigue pitches, while the action of the maximum shear stress together with the polluted gains in the lubricant oil is the exterior driving force for their final formation. A five phase physical model of PIIID DLC/AISI440C bearing fatigue failure is established under cyclic contact stress conditions.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2009年第9期1769-1775,共7页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(50665004)
教育部博士点基金(20060674002)
关键词
等离子体浸没离子注入与沉积
类金刚石碳薄膜
滚动接触疲劳
物理模型
轴承
plasma immersion ion implantation and deposition （PIIID）
diamond-like carbon films
rolling contact fatigue
physical model
bearings
