摘要
为了研究TiAl合金中β相稳定元素对显微组织及相变温度的影响,本文在Ti-43Al合金的基础上,通过单独与复合添加Nb、Cr、Mo 3种合金元素,获得了新型β/γ-TiAl合金,并系统研究了3种元素的作用规律.结果发现:Nb促使合金形成片层结构,Cr、Mo使合金分别形成近γ组织和针状魏氏组织;3种元素对β相的稳定能力为Mo>Nb>Cr;复合添加Nb、Cr、Mo元素对β相的稳定作用比单一添加更为显著;3种不同元素对α+β+γ三相区范围有显著影响,对α2+γ→α转变的共析温度(te)影响较大,而对γ→α的转变温度(tα)影响较小,Ti-43Al-4Nb-2Mo-0.2B合金的α+β+γ三相区最窄约为15℃,而Ti-43Al-6Nb-0.2B合金的α+β+γ三相区最宽约为95℃,Ti-43Al-4Nb-1Cr-1Mo-0.2B合金的α+β+γ三相区为55℃.
To study the effect ofβstabilized elements on microstructure and phase transformation temperature, the novel β/γ-TiAl alloys were obtained by adding Nb, Cr, Mo individually or together into Ti-43Al base alloy. The effects of the additions were studied systematically. It is found that the alloy containing Nb element tends to form lamellar structure, and the alloy containing Cr or Mo element tends to form near γ or widmannstatten structure, respectively. The stabilizing ability on the β phase for the three elements is Mo>Nb>Cr. The addition of combinated Nb, Cr and Mo results in greater influence on stabilizing theβphase than that of the individual addition of Nb, Cr, or Mo. The effects of these three elements on theα+β+γphase region and the eutectoid temperature ( te:α2+γ→α) are prominent and obvious, however the influence on the temperature of γ→α transition ( tα) is not evident. Theα+β+γphase region is the most narrow of only 15 ℃for the Ti-43Al-4Nb-2Mo-0. 2B alloy, the widest is about 95 ℃ for the Ti-43Al-6Nb-0. 2B alloy, and 55 ℃ for the Ti-43Al-4Nb-1Cr-1Mo-0.2B alloy.
出处
《材料科学与工艺》
EI
CAS
CSCD
北大核心
2014年第5期91-96,共6页
Materials Science and Technology
基金
国家重点基础研究发展计划资助项目(2011CB605504)
新金属材料国家重点实验室开放基金资助项目(2012-ZD01)
关键词
钛铝金属间化合物
合金元素
显微组织
晶粒尺寸
相变
TiAl intermetallics
alloying elements
microstructure
grain size
phase transformation
