氮、氧及金属离子注入铝合金表面改性层摩擦磨损性能研究

Friction and Wear Behavior of Aluminum Alloys Ion-implanted with Nitrogen, Oxygen and Metal

在不同温度下对6061铝合金分别进行了氮、氧等离子体浸没离子注入处理,氮与氢混合气体等离子体浸没离子注入处理,以及在氮气氛中的钛或铝等离子体浸没离子注入与沉积处理;采用X射线光电子能谱仪分析了注入改性层的相组成、高温下氧离子注入层的成分及注入离子浓度的深度分布;同时测定了注入改性层的显微硬度及摩擦磨损性能.结果表明:经300℃下氧离子注入处理后铝合金表面形成了较厚的硬质Al2O3层,从而使铝合金表面的耐磨寿命显著延长;经氮/氢混合注入以及氮气氛中金属离子注入和沉积处理后的铝合金表面的抗磨性能显著改善;同单一氮离子注入相比,氮/氢混合注入能更有效地改善铝合金的性能.

6061 aluminum alloy specimens were ion-implanted with nitrogen, oxygen and the mixed gas of nitrogen and hydrogen on a plasma immersion ion implantation (PIII) apparatus operating at different temperatures. They were also ion-implanted with Ti and Al using plasma immersion ion implantation and deposition (MePIID) in low-pressure nitrogen. The chemical states and elemental depth profiles of the modified layers were analyzed by means of X-ray photoelectron spectroscopy (XPS). The microhardness and tribological properties of the modified layers were comparatively investigated using the untreated specimen as a control. As a result, the ion-implantation of the Al alloy with O, N and the mixed gas of nitrogen and hydrogen using PIII greatly increased its microhardness and wear-resistance, while the ion-implantation with Ti and Al using MePIID in low-pressure nitrogen also contributed to increase the microhardness and wear resistance of the Al alloy. This was attributed to the formation of a hard Al2O3 layer on the Al alloy surface subjected to the ion-implantation process, especially the ion-implantation temperature. Thus the modified layers obtained at different ion-implantation temperatures showed differences in the microhardness and wear-resistance. The one after oxygen ion implantation at high temperature showed a longer antiwear life, because in this case the Al2O3 surface layer was more compact and thick.