激光熔覆镍包纳米氧化铝

进行了2Cr13不锈钢表面激光熔覆镍包纳米氧化铝的实验。使用扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线能量色散谱仪(EDAX)、显微硬度仪等设备检测了涂层表面、横截面的显微组织和涂层的硬度、耐磨损等性能,分析了加入纳米氧化铝粒子后对涂层组织和性能的影响。研究结果表明,激光熔覆可获得致密的Fe-Ni(Cr)合金和Al2O3粒子复合涂层。其中,纳米氧化铝粒子弥散分布在微细合金晶粒之间,并与合金晶粒一起形成了胞状树枝晶结构。纳米氧化铝粒子的加入增加了基质金属的成核率,起到了细晶强化以及弥散强化的作用,使得复合涂层的机械性能大幅度提高。复合涂层的平均硬度为700HV0.2,比基体提高了1.5倍,耐磨损性能比淬火态基体提高了1.25倍。

Ni-Coated Nano-Al2O3 Composite Coating Prepared by Laser Cladding

The experiments of laser cladding Ni-coated nano-Al_2O_3 composite powder were made on 2Cr13 stainless steel using(7 kW) CO_2 laser processing system.The microstructure and mechanic performances of coating were tested by scanning electronic microscope(SEM),X-ray diffraction(XRD),energy dispersion analyzer of X-ray(EDAX) and microhardness tester.The changes of microstructure and performances after adding nano-particles were analyzed.The results have shown that the dense Fe-Ni(Cr)/Al_2O_3 composite coating can be got by laser cladding.The coating exhibited a cellular dendritic structure.The XRD data revealed that the phases of composite coating include Al_2O_3,iron nickel alloy and iron chromium alloy.Nano-Al_2O_3 particles enhanced the homogeneous nucleation of metal alloys,refined the crystal grains and strengthened the mechanical properties of coating.The average hardness of composite coating is about 700HV_(0.2),1.5 times higher than that of substrate.Compared with substrate,the abrasion proof has increased by 125%.