热喷涂用NiCrCoAlY-MoSi2纳米复合粉体制备与表征

Preparation and Characterization of NiCrCoAlY-MoSi2 Nanostructured Composite Powders for Thermal Spraying

以MoSi2粉和NiCrCoAlY粉为原料,氩气做保护气,采用高能球磨技术成功制备了NiCrCoAlY-MoSi2纳米金属陶瓷复合粉体。利用X射线衍射仪(XRD)、激光粒度分析仪、扫描电子显微镜(SEM)、振实密度仪和松装密度仪等对粉体的微观组织、晶粒尺寸和性能进行了表征和分析。结果表明:NiCrCoAlY-MoSi2粉体高能球磨30 h,纳米级强化相MoSi2均匀弥散分布在粘结相NiCrCoAlY上,平均晶粒尺寸为25 nm。该粉体由大量椭圆形颗粒和少量细小团聚颗粒组成,流动性能明显改善,可稍加过筛后直接用于热喷涂。

NiCrCoAlY-MoSi2 nanostructured composite powders were synthesized by high energy ball milling with NiCrCoAlY and MoSi2 in an argon atmosphere.The microstructure,grain size and properties of the nanocomposite powders were characterized and analyzed by X-ray diffraction(XRD),laser scattering,SEM,tap-density tester and apparent density tester.The results show that the average grain size of NiCrCoAlY-MoSi2 powders after 30 h milled is 25 nm,and the hard phase nano-MoSi2 is distributed uniformly on the NiCrCoAlY phase.Moreover,the milled powders have excellent fluidity within large number of ellipsoidal particles,which can be directly thermal spraying after sieving.