喷射成形镍基高温合金过喷粉末特征分析  

Characteristics of over-spray powder of a spray formed nickel-base superalloy

作　　者：康福伟[1] 孙剑飞[2] 唐增武[3] 

机构地区：[1]哈尔滨理工大学材料科学与工程学院,哈尔滨150040 [2]哈尔滨工业大学材料科学与工程学院,哈尔滨150001 [3]中国航天三院159厂,北京100074

出　　处：《粉末冶金技术》2010年第3期196-199,203,共5页Powder Metallurgy Technology

基　　金：黑龙江省教育厅资助项目(10051050)

摘　　要：对一种喷射成形镍基高温合金过喷粉末进行了分析。利用激光粒度分布仪、光学显微镜和扫描电镜对粉末形貌、粒度分布、形核方式及显微组织特征进行观察。结果表明,随着粉末颗粒尺寸的减小,颗粒表面变得光滑,形状规整;经测定本试验条件下粉末d50约为46μm;粉末以多种形核方式形核;微观组织以树枝晶为主,当颗粒尺寸小于10μm时,出现了均匀形核现象。过喷粉末的二次枝晶间距随冷却速度而改变,它们之间符合关系式λ2=0.252+0.022B(ε)-m。The characteristics of the over-spray powder of a spray formed nickel-base superalloy were studied in the present investigation.The shapes,size distribution and nucleating modes of the over-spray powder were observed by using optical microscope,scanning electron microscope（SEM）and laser size distribution apparatus.The results show that particle surface becomes smooth with decreasing particle size.The value of d50 is about 46μm by measuring at the testing conditions.The nucleating modes depend on the over-spray powder sizes and cooling rates,but microstructures of the powder are characterized by dendritic structure.When the diameter of the over-spray powder is less than 10μm,the homogeneous nucleation is observed in these powders.By using the experimentally available data,the relationship for describing the secondary dendrite arm space and cooling rates of the studied over-spray powder is established as λ2=0.252＋0.022B（ε）^-m.

关 键 词：喷射成形 过喷粉末 形状 尺寸分布 形核方式 

分 类 号：TG146.15[一般工业技术—材料科学与工程]