纳米Al2O3颗粒增强镍基复合镀层的制备及微观力学性能

采用高能机械化学法配置了纳米Al2O3颗粒镍基复合镀液，并制备了纳米复合镀层。对所得复合镀层的组织和成分进行了分析，采用纳米压痕法研究了复合镀层的硬度、弹性模量等微观力学性能。结果表明，高能机械化学法有效解决了纳米颗粒的团聚，将镀液中85％的颗粒分散至纳米量级，使复合镀层中纳米颗粒的含量提高了53％，复合镀层组织更加致密、均匀；复合镀层的共沉积过程对纳米颗粒的粒径具有自动选择效应，镀层中纳米颗粒尺寸均小于40nm；纳米颗粒复合镀层具有良好的微观力学性能，硬度和弹性模量分别为7．04GPa和225GPa，这是由于纳米Al2O3颗粒对复合镀层具有超细晶强化、硬质点弥散强化、高密度位错强化机制所致。

Preparation and Micro Mechanical Properties of Nano-Al2O3 Particles Reinforced Ni Matrix Composite Coatings

Ni based composite solutions containing nano-Al 2O 3 par ticles were produced by high-energy mechanical and chemical processes. The stru cture and particle content of nano-Al 2O 3/Ni coating were determined, and th e micro mechanical properties were analyzed by nano-indentation technique.The r esults show that 85 percent of particles in the solution are in the size of nano meter, nano-particle content in the coating increases by a factor of 53 per cent and structure of the coating treated by high-energy mechanical and chemica l processes is more compact compared to that of the coating untreated.The size o f nano-particles is self-selected during the deposition of composite coating, and is in the range of less than 40nm.Nano-Al 2O 3/Ni coating exhibits excell ent mechanical properties,and the hardness and Young's modulus are 7.04 GPa an d 225 GPa,respectively, which are attributed to super-fine grain strengthening, dispersion strengthening, high-density dislocations strengthening of nano-Al 2O 3 particles to the composite coating.