γ射线辐照前后高强石墨的摩擦学行为及其磨损机制

Tribological Behavior and Wear Mechanism of High Strength Graphite before and after γ-Ray Irradiation

将硬度和强度不同的两种高强石墨进行γ射线辐照,将辐照前后的石墨与SA 508钢组成摩擦副进行摩擦试验,研究了载荷和润滑条件对高强石墨摩擦学行为的影响,并基于磨损形貌分析了磨损机制。结果表明:硬度、抗压强度较低的高强石墨在低载荷下干摩擦时的摩擦因数小,摩擦稳定;硬度、抗压强度较高的高强石墨在中等载荷下干摩擦时的摩擦因数小,摩擦稳定;在湿摩擦条件下,硬度、抗压强度较低的石墨在低载荷下的摩擦因数和磨损量均较小,在较高载荷下的摩擦因数和磨损量均较大;经大剂量γ射线辐照后,高强石墨的硬度、抗压强度、抗折强度和摩擦学性能基本不变;高强石墨在干摩擦条件下的磨损机制以磨粒磨损为主,伴有疲劳磨损,在湿摩擦条件下的磨损机制以磨粒磨损和冲刷磨损为主。

Two kinds of high strength graphite with different hardness and strength were irradiated byγ-ray,and then friction test was carried out on the friction pairs composed of the graphite and SA 508 steel.The effects of load and lubrication conditions on tribological behavior of high strength graphite were studied,and wear mechanism was analyzed based on the wear morphology.The results show that,dry friction coefficient of the graphite with relative low hardness and compressive strength was small at low load,and the friction was stable.Dry friction coefficient of the graphite with relative high hardness and compressive strength was small under moderate load,and the friction was stable.Under wet friction condition,friction coefficient and wear loss of the graphite with relative low hardness and compressive strength at lower load were small,and friction coefficient and wear loss at higher load were larger.The hardness,compressive strength,flexure strength and tribological properties of high strength graphite were almost unchanged after irradiation.Under dry friction condition,the wear mechanism of high strength graphite was abrasive wear,accompanied by fatigue wear;Under wet friction condition,the wear mechanism was abrasive wear and erosive wear.