通过在表层添加造孔剂TiH₂、在基层添加致密剂酰胺蜡，采用粉末冶金工艺制备基体致密、表层多孔含油的双层铁基轴承材料，利用SEM、XRD等分析材料微观组织与物相分布，用端面摩擦试验机测试其边界润滑工况下的摩擦学性能，结合逐级加载工况下的单、双层铁基材料的摩擦实验结果，分析单、双层烧结材料在不同载荷工况下的供油自润滑机理。结果表明，改变表层中TiH₂的含量可以实现双层材料表层孔隙率和含油率的变化，同时由原位合成反应生成的硬度较高的TiC颗粒可提高材料的表面硬度，满足高承载时的耐磨性能要求，维持摩擦副接触界面和润滑状态稳定。含3.5%TiH₂的双层材料综合力学和摩擦学性能较好；双层材料的疏松表层具有较好的含油自润滑性能，致密基体能增大材料强度，也使润滑油保持在两对偶面之间，综合摩擦学性能和力学性能较单层材料好，适用于重载或复杂润滑工况。

The bilayer porous material with dense substrate layer and variable porosity surface layer was prepared by powder metallurgy technology. TiH₂ was used as the pore former to improve the oil content in the surface layer, and amide wax was used as a dense agent to increase the density and strength of the substrate. The microstructure, phases distribution and the worn surface morphology were characterized by SEM, EDS, XRD, etc. The tribological properties under boundary lubrication conditions were tested by end-face friction tester. The self-lubricating mechanism of single and bilayer sintered materials under different load conditions was analyzed by comparing their friction coefficients under the progressive loading friction test. Results show that adding TiH₂ in the surface layer can effectively improve the porosity and oil ratio of the bilayer materials. Meanwhile, the hard particles TiC generated by the in-situ synthesis reaction have a hard reinforcing effect on the pore channel, which will improve the wear resistance and maintain steady the contact interface and lubrication state of the friction pair. The composite material containing 3.5%TiH₂ has better mechanical and tribological properties. The looser surface layer of the composite material has a better oil self-lubricating property, and the dense substrate can effectively prevent the oil moving downward and keep the lubricant between the friction surfaces. So the comprehensive tribological and mechanical properties of the composite material are better than that of the single-layer material, which is suitable for heavy load or complex lubrication conditions.