热挤压成形用纳米Fe_3O_4粒子改性润滑油润滑性能研究

采用化学共沉淀法制备了表面经油酸修饰的纳米Fe3O4粒子,在透射电镜下研究了纳米粒子的粒径大小、形貌及其分散性,在MRS-10D四球摩擦试验机上测试了添加纳米Fe3O4粒子润滑油的承载能力,在CSS-2220型电子万能试验机上,研究了添加纳米Fe3O4粒子的润滑油在LY12热挤压成形过程中的润滑性能,并与传统的添加微米级石墨润滑油的润滑性能和润滑效果进行了对比。试验结果表明:所制备的纳米Fe3O4粒子呈球形、平均粒径为10nm,在润滑油中具有很好的分散性,用其作润滑油添加剂时,可以明显改善润滑油的承载能力;与微米级石墨粉作热挤压润滑油添加剂的润滑性能相比,添加纳米Fe3O4粒子的润滑油可使挤压时的挤压力明显降低,在所添加的体积浓度相同时,最大可使挤压力降低32%,同时避免了被挤压件表面残碳现象的发生,提高了被挤压件的表面质量。

Investigation of Lubricating Properties of the Lubricating Oil Added Fe_3O_4 Nanoparticles in the Hot Extrusion of LY12

The surface-modified Fe_ 3 O_ 4 nanoparticles were prepared using chemical method.The size and shape distribution of the nanoparticles were studied by transmission electron microscopy. The load-bearing capacity of the lubricating oil added Fe_ 3 O_ 4 nanoparticles was evaluated with a four-ball tester.Lubricating properties of the lubricating oil added Fe_ 3 O_ 4 nanoparticles were investigated in the hot extrusion of LY12 using an electron omnipotence tester.The experimental results indicate that the average diameter of the OA-coated Fe_ 3 O_ 4 particles having good dispersion capacity in oil is about 10 nm, and the shape of the prepared nanoparticles is approximately spherical.The load-bearing capacity of the lubricating oils added nanoparticles can be improved obviously.Compared with the lubricating effect of micron-size graphite powder as lubricating oil additive, Fe_ 3 O_ 4 nanoparticles not only can strikingly reduce hot extrusion force, but also can improve the surface finish of the hot-extruded workpiece.