Effect of Nanocrystalline Surface and Iron-containing Layer Obtained by SMAT on Tribological Properties of 2024 Al Alloy

摘要:

采用表面机械研磨处理技术，选用陶瓷球和钢球作为弹射介质，在 2024 铝合金表面分别制备出纯净的纳米晶层和含铁纳米晶层。表面机械研磨处理前后2024铝合金摩擦磨损性能在载荷为1.5 N的条件下与直径为 5 mm 的 GCr15 钢球对磨进行了研究。结果表明，表面机械研磨处理 30 min 后，陶瓷球处理铝合金表面纳米晶层平均晶粒尺寸达到 49.2 nm，钢球处理铝合金表面纳米晶层平均晶粒尺寸细化到 52.1 nm。此外，采用钢球作为弹射介质进行表面机械研磨处理在纳米晶表层引入了厚度约为 5 μm 的含铁层。在晶粒细化、硬度增加和含铁层的润滑作用共同作用下，2024铝合金的耐磨性能得到显著改善

Abstract:

The pure and Fe-containing nanocrystalline layers were fabricated on the surface of 2024 Al alloy by surface mechanical attrition treatment (SMAT) using ceramic balls and steel balls, respectively. The friction and wear properties of 2024 Al alloy before and after SMAT were investigated by sliding against a GCr15 steel ball of 5 mm in diameter at a load of 1.5 N. The results demonstrate that the surface nanocrystalline layers with average grain sizes of 49.2 and 52.1 nm can be obtained by using ceramic balls and steel balls, respectively, when treated for 30 min. Moreover, a 5 μm thick surface layer containing Fe is also introduced into the Al nanocrystalline surface when treated using steel balls. The wear resistance of 2024 Al alloy is improved due to the combination of grain refinement, increased hardness and lubrication effect of iron-containing layer