摘要
采用等离子电极旋转雾化法和热等静压法(hot isostatic press,HIP)分别制备FGH96粉末与合金,对原始及高温(1 150℃)预热处理后的FGH96粉末表面析出相以及HIPed FGH96合金的原始粉末颗粒边界(prior particleboundary,简称PPB)进行分析,进而研究PPB对合金室温和750℃拉伸断裂行为的影响。研究发现:原始粉末表面无明显析出相,1 150℃预热处理后粉末表面有块状MC和细小氧化物分布;热等静压法制备的FGH96合金及其热处理后,PPB析出相主要由颗粒和块状的金属碳化物MC及富Zr的氧化物颗粒组成;该合金经过固溶和时效处理后,颗粒状MC部分溶解而块状MC长大,PPB碳化物的尺寸分布由单峰分布转变为双峰分布;常温拉伸时微孔在PPB上形成并扩展,合金沿PPB断裂;750℃拉伸时,合金强度与塑性较常温下明显降低,部分M23C6在晶界析出,块状和颗粒状碳化物部分溶解,为M23C6提供碳源,合金断口呈现沿晶和沿PPB混合断裂的形貌。
The precipitates on the prior and 1 150 ℃ vacuum-treated FGH96 powder surface, as well as the prior partiele boundary （PPB） were investigated. Besides, the influences of PPB precipitate during tensile test at room temprature and 750℃ were also studied. The results show that precipitates seldom distribute on the surface of the prior powders. Block shaped carbides MC and oxide particles are observed on the surface of the powders treated at 1 150 ℃. PPB precipitates of hot isostatic pressed （HIPed） and heat treated （HTed） FGH96 alloy are made up of block-shaped MC, granular MC and Zr rich oxides particles. After solution and aging treatment, the block carbides grow up and the rounded carbides partly dissolve. As a result, the particle size distribution of PPB carbides changes from unimodal distribution of HIPed alloy to bimodal distribution of HTed alloy. When tension testing performs at room temperature, the micro flaws form around PPB of carbides and then enlarge, which results in the fracture along PPB. As the tension temperature increases to 750 ℃, M23C6 carbides precipitate at the grain boundary, block-shaped and granular carbides serving as a carbon resource partly dissolved. The fracture surface of 750 ℃ specimen shows a mixture fracture mechanism of grain boundary and PPB fracture,
出处
《粉末冶金材料科学与工程》
EI
北大核心
2013年第1期1-7,共7页
Materials Science and Engineering of Powder Metallurgy
基金
国家重点基础研究发展计划(973计划)资助项目(2010CB631204)
