Ni-Cu-Re合金自生氧化膜的减摩机理

FUNDAMENTAL OF LUBRICATION WITH OXIDE FILM OF Ni-Cu-Re AT ELEVATED TEMPERATURE

用旋转式高温销盘摩擦试验机测定了 Ni、Ni-Re,Ni-Cu、Cu-Re 及 Ni-Cu-Re 等合金摩擦系数随温度的变化;用 X 射线测定了磨屑及氧化层、Ni-Cu-Re 550℃的挥发物结构;能谱测定了磨屑、氧化膜及近表层成分,还进行了静态氧化实验,试验发现高温摩擦实验后样品近表层有富 Re 层,它不利于氧化膜的形成,但降低了合金的氧化速度,提高了耐磨性,试验结果还表明了Ni-Cu-Re 系高温摩擦系数较低(0.2-0.3),原因是 Cu,Re 共同作用形成易挥发性氧化物起的润滑作用,提出了氧化膜的减摩模型。

The variations of friction coefficient vs temperature of Ni-Cu-Re,Ni-Re,Ni-Cu,Cu-Reand pure Ni were determined by pin on disc wear device.The structures of oxide film,wear debris and vol-atile substance were identified by X-ray diffraction;the composition of oxide film and subsurface was ex-amined by SEM-EDX.A Re-rich layer near surface of Ni-Cu-Re ally was observed after elevated tem-perature testing.The existence of Re-rich layer was advantage to improve the oxidation and wear resist-ance of alloy and disadvantage to form soft oxide film with lubrication.The decrease of friction coefficientof Ni-Cu-Re at elevated temperature resulted from the volatile oxides of Cu and Re.The model aboutlubrication with naturally occuring oxide film has been suggested.