机械工程

多组元微合金化高铌TiAl基合金微观组织的研究

展开
  • 沈阳航空航天大学 材料科学与工程学院, 沈阳 110136
王艳晶(1973-), 女, 吉林农安人, 副教授, 主要研究方向:金属间化合物, E-mail:wangyj2008@gmail.com。

收稿日期: 2012-09-20

基金资助

国家自然科学基金项目(项目编号:50801047)

Study on microstructure of multi-component micro-alloying TiAl-based alloy with high Nb content

Expand
  • School of Material Science and Engineering, Shenyang Aerospace University, Shenyang 110136

Received date: 2012-09-20

摘要

研究了B、Hf、Y微合金化高铌TiAl基合金的铸态及热处理后的微观组织。光学显微组织观察表明, B、Hf、Y微合金化高铌TiAl合金铸态组织为近层片组织, 其α2/γ层片团得到细化;XRD分析表明, 除了α2和γ相, 在铸态组织中还含有β(B2)、Y2O3、YAl2。扫描电镜结合能谱分析表明, β(B2)相分布在层片团的边界附近, 粒状Y2O3和YAl2分布在晶内和晶界, 硼化物以条状或粒状分布在晶内和晶界。经过1260℃/20h + 900℃/30min/AC热处理后, 得到由α2/γ细小层片团与等轴γ晶粒组成的双态组织, β(B2)相基本消除, 同时YAl2相消失, 形成了富Hf的Y2O3和富Nb的钛硼化物。

本文引用格式

王艳晶, 宋玫锦, 王继杰, 杜兴蒿 . 多组元微合金化高铌TiAl基合金微观组织的研究[J]. 沈阳航空航天大学学报, 2013 , 30(1) : 66 -70 . DOI: 10.3969/j.issn.2095-1248.2013.01.015

Abstract

The as-cast and heat-treated microstructure of B, Hf, Y micro-alloyed TiAl-based alloy with high Nb content were investigated. The OM observation shows that, the as-cast microstructure of B, Hf, Y micro-alloyed TiAl-based alloy was near lamellar microstructure in which α2/γ lamellar colonies were refined. The XRD analysis shows that, besides α2 and γ phase, β(B2), Y2O3, YAl2 were also included in the as-cast microstructure. The analysis of SEM combined with EDS shows that the β(B2) phase was distributed near the lamellar colonies grain boundaries, granular Y2O3 and YAl2 , and granular or strip boride existed in grains and grain boundaries . After heat treatment at 1260℃ for 20h, at 900℃ for 30min and subsequent air-cooling, the duplex microstructures composed with thin α2/γ lamellar and γ equiaxed axis grains were obtained in the alloy, the β(B2) phase has been basically eliminated, simultaneously the YAl2 has disappeared, and meanwhile Hf-rich Y2O3 and Nb-rich titanium boride phases formed.

参考文献

[1]Loria E A.Gamma Titanium Aluminides as prospective structural materials[J].Intermetallics, 2000, 8(9-11):1339-1345.
[2]Dimiduk D M.Gamma Titanium Aluminide Alloys-An assessment within the competition of aerospace structural materials[J].Materials Science and Engineering, 1999, 263(2):281-288.
[3]Ramanujan R V.Phase transformations in Gamma based Titanium Aluminides[J].International Materials Reviews, 2000, 45(6):217-240.
[4]李宝辉, 孔凡涛, 陈玉勇, 等.TiAl金属间化合物的合金设计及研究现状[J].航空材料学报, 2006, 26(2):72-78.
[5]郑立静, 杨莉莉, 张虎.微量元素B在γ-TiAl基合金的应用研究进展[J].稀有材料与工程, 2010, 39(10):1875-1880.
[6]Carl Lund.Effects of refractory additions on the structure and mechanical properties of a Hf containing nickel base superalloy[C].Superalloys, 1980.
[7]HUANG Z W.Inhomogeneous microstructure in highly alloyed cast TiAl-based alloys caused by microsegregation[J].Scripta Mater, 2005( 52):1021-1025.
[8]许正芳.热处理消除大尺寸铸态高Nb-TiAl基合金组织中的β相偏析[J].材料加工, 2007(9):42.
[9]Brossmann U, Oehring M, Appel F, et al.Microstructure and chemical homogeneity of high Nb gamma based TiAl alloys in different conditions of processing[C].Structural Intermetallics, Warrendale.PA:TMS, 2001.
[10]Chen Y Y, Kong F T, Han J C, et al.Influence of yttrium on microstructure, mechanical properties and deformability of Ti-43Al-9V alloy[J].Intermetallics, 2005, 13(3/4):263.
[11]张莉.含Hf铸造钛铝基合金组织细化及其机制研究[D].哈尔滨:哈尔滨工业大学博士论文, 2009.
[12]J.A.Christodoulou, H.M.Flower.The Role of Borides in Near-γ Titanium Aluminides[J].Advanced Engineering Materials, 2000, 2(10):631-638.
[13]陈国良, 林均品.有序金属间化合物结构材料物理金属学基础.北京:冶金工业出版社, 1999.
[14]郑瑞廷, 张永刚, 陈昌麒, 等.循环热处理工艺对双态复相γ-TiAl基合金显微组织的影响[J].金属热处理, 2001, 26(10):12.
[15]李阁平.高温钛合金中稀土相的形貌、结构、形成及微观力学行为[D].沈阳:中国科学院金属研究所博士学位论文, 1995.
[16]陈宝辉.含钇的TiAl基合金显微组织及性能的研究[D].哈尔滨:哈尔滨工业大学博士论文, 2007.
文章导航

/