【摘要】 用气雾化(GA)和水雾化(WA)工艺制备CoNiCrAlY粉末并测定其流动性和松装密度，将其作为初始粉末用超音速火焰喷涂工艺制备CoNiCrAlY涂层并进行真空热处理，采用XRD分析物相、用金相显微镜和扫描电镜分析显微结构和用万能试验机测试涂层的结合强度。结果表明，与WA相比，用GA制备的CoNiCrAlY粉末为球形或近球形，流动性好、松装密度大，制备的涂层结构致密均匀，β相含量高，孔隙率低，结合强度和硬度高。真空热处理后的两种涂层中粒子明显融合，β相的含量提高且分布更为均匀，孔隙率降低，硬度降低。真空热处理使WA涂层的结合强度提高，但是涂层内仍有较大的孔隙。真空热处理态的GA涂层，其抗氧化性能优异。更多还原

【Abstract】 Two type powders of CoNiCrAlY alloy were prepared by gas atomization (GA) and water atomization (WA) respectively,then which were used as feedstock powders to further prepared the corresponding coatings on a directionally solidified high temperature alloy DZ411by using high velocity oxygen fuel (HVOF) technique and subsequently they were subjected to proper subsequent vacuum heat treatment.The flowability and apparent density of the prepared powders were measured according to GB/T1484 and GB/T 1479.Meanwhile,the phase composition,microstructure,microhardness,and adhesive strength to the substrate of the prepared coatings were characterized via optical microscopy and scanning electron microscopy,automatic hardness tester,and universal testing machine.The high temperature oxidation performance of the coatings/DZ411 was assessed in air at 1050~oC for 200 h.The results show that compared with WA,the CoNiCrAlY powder prepared by GA is spherical or nearly spherical,with good flowability and high apparent density.The prepared GA coating has a dense and uniform structure with high β phase content,low porosity,high adhesive strength and high microhardness.After vacuum heat treatment,mutual fusion of particles was clearly observed within the two coatings,while the amount of β phase increases and its distribution becomes much more uniform,correspondingly,their porosity and microhardness decrease.The adhesive strength of WA coating after vacuum heat treatment has been improved,but there are still larger pores within the coating.The vacuum heat treated GA coating presents much better oxidation resistance.更多还原