采用双步球磨法和放电等离子烧结技术制备细晶Ti-45Al-5.5(Cr,Nb,B,Ta)(摩尔分数,%)合金,利用扫描电子显微镜(SEM)和X射线衍射仪(XRD)等对球磨后的粉末形貌、相组成以及烧结块体的显微组织结构进行观察和分析,研究烧结温度对Ti-45Al-5.5(Cr,Nb,B,Ta)合金显微组织和力学性能的影响.结果表明:双步球磨粉末的颗粒形状较规则,其颗粒尺寸为10～40 μm,内部结构较均匀,主要由TiAl和Ti3Al相组成;放电等离子烧结后的块体主要由主相TiAl、少量的Ti3Al相及Ti2Al和TiB2相组成;当烧结温度为1 000 ℃时,烧结块体主要为等轴晶组织,等轴晶粒平均尺小于500 nm;当烧结温度为1 100 ℃时,烧结块体致密、无孔洞,部分等轴晶粒明显长大;随着烧结温度的升高,Ti-45Al-5.5(Cr,Nb,B,Ta)合金的显微硬度随之增大,抗压强度和抗弯强度却随之降低;压缩断口形貌分析表明:Ti-45Al-5.5(Cr,Nb,B,Ta)合金在1 000 ℃时,属于沿晶断裂,在1 100 ℃时,断口以沿晶断裂为主,存在部分解理断裂.弯曲断口形貌分析表明:Ti-45Al-5.5(Cr,Nb,B,Ta)合金以沿晶断裂为主,存在部分解理断裂.
参考文献
| [1] | N. Forouzanmehr;F. Karimzadeh;M.H. Enayati .Study on solid-state reactions of nanocrystalline TiAl synthesized by mechanical alloying[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2009(1/2):93-97. |
| [2] | Alain Couret;Guy Molenat;Jean Galy .Microstructures and mechanical properties of TiAl alloys consolidated by spark plasma sintering[J].Intermetallics,2008(9):1134-1141. |
| [3] | Prajina Bhattacharya;Pascal Bellon;Robert S. Averback .Nanocrystalline TiAl powders synthesized by high-energy ball milling: effects of milling parameters on yield and contamination[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2004(1/2):187-196. |
| [4] | K.I.Moon;K.S.Lee .A study of the microstructure of nanocrystalline Al-Ti alloys synthesized by ball milling in a hydrogen atmosphere and hot extrusion[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,1999(1/2):312-321. |
| [5] | LI Z W;GAO W;ZHANG D L;CAI Z H .High temperature oxidation behaviour of a TiAl-Al2O3 intermetallic matrix composite[J].Corrosion Science,2004,46(08):1997-2007. |
| [6] | Y. Wu;S. K. Hwang .Microstructural refinement and improvement of mechanical properties and oxidation resistance in EPM TiAl-based intermetallics with yttrium addition[J].Acta materialia,2002(6):1479-1493. |
| [7] | 李东辉,吴玉程,李云,龚明,郑玉春.机械球磨与不同温度烧结下的TiAl合金研究[J].合肥工业大学学报（自然科学版）,2006(08):969-971,975. |
| [8] | 路新,何新波,李世琼,曲选辉.放电等离子烧结TiAl基合金的显微组织及力学性能[J].北京科技大学学报,2008(03):254-257. |
| [9] | 李书江,王艳丽,林均品,林志,陈国良.微量C,B对高铌TiAl合金显微组织与力学性能的影响[J].稀有金属材料与工程,2004(02):144-148. |
| [10] | 史耀君,杜宇雷,陈光.高铌钛铝基合金研究进展[J].稀有金属,2007(06):834-839. |
| [11] | Yang SJ.;Nam SW. .Investigation of alpha(2)/gamma phase transformation mechanism under the interaction of dislocation with lamellar interface in primary creep of lamellar TiAl alloys[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2002(0):898-905. |
| [12] | Y.H. Wang;J.P. Lin;Y.H. He .Microstructural characteristics of Ti-45Al-8.5Nb/TiB_2 composites by powder metallurgy[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2009(1/2):505-511. |
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