The Microstructure of EP741NP Powder by PREP and Heat
The EP741NP powder was fabricated by methods of plasma rotating electrode process(PREP),followed by heat treatment.Microstructure analyzing of both as-powder and heat treatment was carried out.The results show that the surface cleanliness and homogeneity of the powder prepared by PREP are favorable.The oxygen content of PREP powder is less than 0.01%.No obvious change of the particle surface could be observed until the powder was heat treated to 900℃ and above,at which temperature very fine precipitates were formed on the particle surface.At increased temperatures the precipitates coarsened and became more discrete.The back-scatter electron SEM micrographs show that,the previously mentioned segregation of high atomic number elements such as Hf at interdendritic regions was not completely removed until the powders were heat treated to 1100℃,which may be associated with the formation of the Hf particles on the surfaces of heat treated powders.EDX analysis shown that precipitates formed on the particle surface during heat treatment were rich in Hf and O,which may be assigned as Hf oxides.On the other hand,no Hf was found on the particle surface of original powders.It seemed that the Hf which contributed to the formation of precipitates on particle surface during high temperature heat treatment may have come from the interior through diffusion,which finally led to the elimination of Hf segregation in the interior of particles as described above.
EP741NP Powder PREP Heat treatment Hf precipitates
Han Zhiyu Fei Yan Liang Shujin Wang Qingxiang Lai Yunjin Zhang Pingxiang
Sino-Euro Materials Technologies of Xian Co.,Ltd.,Xian 710018,China;School of Materials Science an Sino-Euro Materials Technologies of Xian Co.,Ltd.,Xian 710018,China Northwest Institute for Nonferrous Metal Research,Xian 710016,China
国际会议
北京
英文
71-75
2018-09-16（万方平台首次上网日期，不代表论文的发表时间）