(西北有色金属研究院 金属多孔材料国家重点实验室，西安 710016)
摘 要: 利用水冷铜坩埚熔炼、高纯氩气雾化技术制备出高品质球形TC4合金粉末。将石墨导流管的内壁用Y2O3与无水乙醇配比的涂料进行涂覆，分析其对雾化粉末间隙元素的影响，总结气雾化粉末的间隙元素来源及控制建议，并对不同粒度粉末的显微组织进行表征。结果表明:石墨导流管内壁在无涂层的情况下，雾化粉末的碳含量较大;而导流管内壁的Y2O3涂层能有效降低碳对钛合金污染的风险;粉末间隙元素含量随着粒径的减小而增大;粒径较大粉末的表面为胞状晶组织，而小尺寸粉末表面光滑且无明显结晶组织;由于快速凝固的原因，粒径较大粉末的内部主要由α相胞晶和针状马氏体α′相组成，小粒径粉末的内部组织明显细化，全部为蜂窝状的胞状晶 组织。
关键字: TC4合金;气雾化;涂层;球形粉末
（State Key Laboratory of Porous Metal Materials,
Northwest Institute for Nonferrous Metal Research, Xi’an 710016, China）
Abstract:The spherical TC4 alloy powders were produced by gas atomization using water-cooled copper crucible and argon gas with high purity. The Y2O3 layer was coated onto the inner wall of the graphite nozzle. The interstitial level of the gas-atomized powders with various particle sizes was analyzed to investigate the effect of coating. The sources of interstitial content for gas-atomized powders were also discussed and related suggestions for its control were provided. Besides, the microstructures of gas-atomized powders with various particle sizes were also characterized in terms of surface morphology and cross-sectional structures. The results show that the Y2O3 coating can effectively prevent the gas-atomized powders from carbonization by graphite nozzle as comparing with or without coating. The interstitial component of the gas-atomized TC4 powders increases with the particle size decreasing. The surface of coarse powders exhibits the cellular structure with equiaxed grains. However, the fine powders achieve smooth surfaces and can not be observed any crystallization. Because of rapid solidification, both α cells and acicular martensite α′ phases are observed in the internal area of coarse powders, while only honeycomb cellular structure is demonstrated with refined grains in fine powders.
Key words: TC4 alloy; gas atomization; coating; spherical powder
