摘要
采用等离子束熔炼工艺制备了名义成分为Ti-45A l-8.5Nb-0.2W-0.2B-0.02Y（at%）的大尺寸铸锭,经机加工后,采用无坩埚感应加热连续Ar气雾化工艺制备出合金粉,并研究了其特性。结果表明,大尺寸高Nb-TiA l合金铸锭为全片层组织,主要存在三种微观偏析：β相、硼化物和氧化钇。高Nb-TiA l合金粉的粒度主要分布在100-200μm;氧含量随着合金粉的粒度变细而逐渐增大;氮含量不随合金粉粒度的变化而变化;另外,还存在极少量的碳。高Nb-TiA l合金粉的相组成与粒度密切相关,-200目粉只存在α2相,随着粒度变粗,γ相逐渐增多,α2相逐渐减少。高Nb-TiA l合金粉的表面和内部组织均呈枝状;内部组织存在四种成分偏析,随着粒度变细,偏析细化。
Ti-45Al-8.5Nb-0. 2W-0. 2B-0. 02Y （at%） ingot with industrial scale was fabricated using plasma arc furnace and was subsequently machined. High Nb containing TiAl alloying powder was obtained by Ar gas atomization process and its characterization was investigated. It was found that there are three microsegregations in the high Nb containing TiAl alloy composed of fully lamellar microstructure, i.e. β phase, borides and Y2O3. The granularity of high Nb containing TiAl alloying powder is mostly 100 - 200μm ; Oxygen content becomes higher gradually with decreasing powder granularity; Nitrogen content is basically constant; and little carbon exists. The phases of the alloying powder are related with its granularity. The exterior and interior micro-structures of the alloying powder are dendritic. There are four microsegregations in the powder, and they become finer with decreasing powder granularity.
出处
《航空材料学报》
EI
CAS
CSCD
2007年第5期34-39,共6页
Journal of Aeronautical Materials
基金
高等学校科技创新工程重大项目资助(704008)
新世纪优秀人才项目资助(NCET-04-01017)
关键词
TIAL合金
粉末冶金
合金粉
特性
TiAl alloy
powder metallurgy
alloying powder
characterization
