【作者】 沈卫平； 蒋媛媛； 范慧卿； 葛昌纯；

【Author】 SHEN Wei-Ping,JIANG Yuan-Yuan,FAN Hui-Qing,GE Chang-Chun(Institute of Special Ceramicsand Powder Metallurgy,School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China)

【机构】 北京科技大学材料科学与工程学院特种陶瓷粉末冶金研究所；

【摘要】 高温合金粉末在制备过程中希望避免外来夹杂物,氧含量低。研究结果表明,燃烧合成可以制备毫米级镍基高温合金颗粒,颗粒粒度的大小与料层的厚度成正比。燃烧合成制备高温合金颗粒,可以避免因熔炼工艺冲刷耐火材料带来的污染,可消除外来大尺寸氧化物夹杂造成的危害,观测到内生夹杂物为球形,尺寸小于20μm。燃烧合成制备高温合金颗粒,冷却速度低于氩气雾化、等离子旋转电极雾化等快速冷凝工艺,有析出相。燃烧合成高温合金3 mm颗粒中出现了枝状晶,燃烧合成高温合金颗粒可以把偏析限制在颗粒的尺寸内。但用铝热还原法燃烧合成高温合金颗粒需要控制铝含量。更多还原

【Abstract】 It is difficult for superalloy powders to avoid exogenous non-metallic inclusions during preparation,and fine powders are easy to be oxidized.In this paper Ni-based superalloy granules within 3 mm can be prepared by combustion synthesis,and the size of grains is in direct ratio to the thickness of bed of initial powders.This method also can avoid contamination from eroding refractories in smelting,and prevent harm from external large dimension oxide inclusions.The endogenous inclusions are with spherical shape and less than 20μm.The cooling rate of superalloy granules prepared by combustion synthesis is lower than quick condensation process,such as: argon atomization,plasma rotation electrode process etc.,hence precipitated phases emerge.There are dendrite crystals in 3 mm superalloy granules prepared with combustion synthesis.The dendritic segregation can be limited within granule size.The prior particle boundary is discontinuous in sintered superalloy with spark plasma sintering.更多还原