4. 结论
Ti–47Al–2.5V–1Cr 和 Ti–40Al–2Cr (at.%) 金属间化合物合金通过激光沉积（LMD）制造工艺制造。由γ- TiAl和α2-Ti3Al构成的完全片状显微结构（FL）激光沉积形成γ-TiAl 样品。Ti–40Al–2Cr合金1100℃退火30分钟伴随无功电量可以获得晶粒度大小约为20um的均匀的微观组织 。Ti–47Al–2.5V–1Cr经过1125 ℃/30 min退火处理伴随无功电量，可获得晶粒大小约为100um微观组织。Ti–47Al–2.5V–1Cr合金伴随无功电量经1125 ℃/30min退火处理后沿纵向方向，其室温抗拉强度高达650 MPa。Ti–40Al–2Cr合金经1100 ℃/30min退火处理之后空冷，其室温抗拉强度沿纵向方向高达630 MPa。这种合金的延伸率至多为0.6%，这表明其延展性非常低。
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鸣谢
本研究由国家基础研究项目(2006CB605206-2)和中国国家自然科学基金委员会(批准号No. 50625413)以及中国教育部长江学者创新研究小组资助研究。
参考文：
[1] Liu CT, Schneibel JH, Maziasz PJ, Wright JL, Easton DS. Tensile properties and fracture toughness of TiAl alloys with controlled microstructures. Intermetallics 1996;4:429–40.
[2] Liu CT, Maziasz PJ. Microstructural control and mechanical properties of dual-phase TiAl alloys. Intermetallics 1998;6:653–61.
[3] Kim YW, Karthikeyan S, Viswanathan GB, Gouma PI, Vasudevan VK, Mills MJ. Mechanisms and effect of microstructure on creep of TiAl-based alloys. Mater Sci Eng A 2002;329:621–30.
[4] Novoselova T, Malinov S, Sha W. Experimental study of the effects of heat treatment on microstructure and grain size of a gamma TiAl alloy. Intermetallics 2003;11:491–9.
[5] Yamaguchi M, Kishida K, Inui H, Yao KF. Plastic deformation of V- and Zr-alloyed PST TiAl in tension and compression at room temperature. Acta Metall Mater 1995;43:1075–86. [6] Sun ZM, Hashimoto H. Fabrication of TiAl alloys by MA-PDS process and the mechanical properties. Intermetallics 2003;11:825–34.
[7] Sun ZM, Hashimoto H, Wang Q, Tada S, Toshihiko A. Synthesis and consolidation of TiAl by MA-PDS process from sponge-Ti and chip-Al. Intermetallics 2003;11:63–9.
[8] Wen CE, Yasue K, Yamada Y. Fabrication of TiAl by blended elemental powder semisolid forming. J Mater Sci 2001;36:1741–5.
[9] Jakob A, Speidel MO. Microstructure and tensile properties of TiAl compounds formed by reactive foil metallurgy. Mater Sci Eng A 1994;189:129–36.
[10] Zhang XD, Brice C, Mahaffey DW, Zhang H, Schwendner K, Evans DJ, et al. Direct laser deposition of alloys from elemental powder blends. Scripta Mater 2001;44:2419–24.
[11] Wang HM, Zhang LY, Li A, Cai LX, Tang HB. Rapid solidi?cation laser processing and forming of advanced aeronautical metallic materials. J Beijing Univ Aeronaut Astronaut
- 12 -
2004;30:962–7.
[12] McCullough C, Valencia JJ, Levi CG, Mehrabian R. Solidi?cation microstructure of supercooled Ti–Al alloys containing intermetallic phases. Acta Metall Mater 1989;37:1321–36. [13] Grif?th ML, Schlienger ME, Harwell LD, Oliver MS, Baldwin MD, Ensz MT, et al. Understanding thermal behavior in the LENS process. Mater Des 1999;20:107–13.
[14] Wang JN, Xie K. Re?ning of coarse lamellar microstructure of TiAl alloys by rapid heat treatment. Intermetallics 2000;5:545–8.
[15] Cao GX, Fu LF, Lin JG, Zhang YG, Chen CQ. The relationships of microstructure and properties of a fully lamellar TiAl alloy. Intermetallics 2000;5:647–53.
[16] Koeppe C, Bartels A, Clemens H, Schretter P, Glatz W. Optimizing the properties of TiAl sheet material for application in heat protection shields or propulsion systems. Mater Sci Eng A 1995;201:182–93.
[17] Gerling R, Bartels A, Clemens H, Kestler H, Schimansky FP. Structural characterization and tensile properties of a high niobium containing gamma TiAl sheet obtained by powder metallurgical processing. Intermetallics 2004;12:275–80.
[18] Kumpfert J, Kim YW, Dimiduk DM. Effect of microstructure on fatigue and tensile properties of the gamma TiAl alloy Ti–46.5Al–3.ONb–2.1Cr–0.2W. Mater Sci Eng A 1995;192:465–73.
[19] Gerling R, Schimansky FP, Stark A, Bartels A, Kestler H, Cha L, et al. Microstructure and mechanical properties of Ti–45Al–5Nb + (0–0.5C) sheets. Intermetallics 2008;16:689–97. [20] Liu CT, Wright JL, Deevi SC. Microstructures and properties of a hot-extruded TiAl containing no Cr. Mater Sci Eng A 2002;329:416–23.
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