Effect of Yttrium Addition on Microstructures and Room Temperature Tensile Properties of Ti-47Al Alloy
来源期刊：JOURNAL OF RARE EARTHS2006年第3期
论文作者：Chen Yuyong Li Baohui Kong Fantao
Key words：TiAl alloy; microstructure; property; yttrium; rare earths;
Abstract: The microstructures and room temperature tensile properties of a series of Ti-47Al-xY (χ = 0%, 0.1%,0.3 %, 0.5 %, 0.7 % and 1.0 % (atom fraction) ) were investigated systemically. Results show that both the grain size and lamellar spacing decrease remarkably with the increase of Y content. When the content of Y is greater than 0.1%,most of the Y elements accumulate along the grain boundaries and some fine particles are uniformly dispersed within the grains in the form of YAl2 compound because of the low solubility and segregation of Y in TiAl alloys. Grain-boundary segregation of Y element is more prominent with the increase of Y addition. Good tensile properties are obtained when Y addition ranges from 0.3 % to 0.5 %. The refinement of grain and lamellar structures and dispersion of YAl2 within the grains contribute to the improvement of tensile properties. On the other hand, for high Y-added alloys (over 0.5 % Y), tensile properties are obviously deteriorated due to brittle cleavage fracture of the coarse YAl2 network.
Chen Yuyong1，Li Baohui1，Kong Fantao1
(1.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)
Abstract:The microstructures and room temperature tensile properties of a series of Ti-47Al-xY (χ = 0%, 0.1%,0.3 %, 0.5 %, 0.7 % and 1.0 % (atom fraction) ) were investigated systemically. Results show that both the grain size and lamellar spacing decrease remarkably with the increase of Y content. When the content of Y is greater than 0.1%,most of the Y elements accumulate along the grain boundaries and some fine particles are uniformly dispersed within the grains in the form of YAl2 compound because of the low solubility and segregation of Y in TiAl alloys. Grain-boundary segregation of Y element is more prominent with the increase of Y addition. Good tensile properties are obtained when Y addition ranges from 0.3 % to 0.5 %. The refinement of grain and lamellar structures and dispersion of YAl2 within the grains contribute to the improvement of tensile properties. On the other hand, for high Y-added alloys (over 0.5 % Y), tensile properties are obviously deteriorated due to brittle cleavage fracture of the coarse YAl2 network.
Key words:TiAl alloy; microstructure; property; yttrium; rare earths;
【全文内容正在添加中】
