Ti-22Al-24Nb-0.5Mo粉末合金的制备及电子束焊接*
PREPARATION OF POWDER METALLURGY Ti-22Al-24Nb-0.5Mo ALLOYS ANDELECTRON BEAM WELDING
Received date: 2016-01-08
Online published: 2016-07-08
采用预合金粉末热等静压工艺制备了Ti-22Al-24Nb-0.5Mo (原子分数, %)粉末合金, 对Ti-22Al-24Nb-0.5Mo粉末合金环坯和板坯进行电子束焊接. 采用OM, SEM, EPMA和X射线三维成像技术对焊接接头的微观组织进行表征, 研究了焊后热处理对焊接接头显微硬度、拉伸性能和持久性能的影响. 结果表明, 热等静压温度显著影响Ti-22Al-24Nb-0.5Mo粉末合金的孔隙分布. 在1030 oC热等静压成型的粉末环坯经980 oC, 2 h, 真空炉冷热处理后表现出较好的可焊性. 焊接接头熔合区、热影响区和母材的化学成分均匀, 虽然显微组织差异明显, 但是显微硬度无明显区别. 拉伸及持久性能测试试样皆断裂于熔合区. 焊接接头熔合区存在大量的显微孔隙是焊接接头发生断裂的失效机制. 焊后热处理可以减少焊缝处的显微孔隙数量, 从而提高焊接接头塑性及高温持久寿命.
关键词： 热等静压; Ti-22Al-24Nb-0.5Mo粉末合金; 微观孔隙; 电子束焊接
吴杰 , 徐磊 , 卢正冠 , 崔玉友 , 杨锐 . Ti-22Al-24Nb-0.5Mo粉末合金的制备及电子束焊接*[J]. 金属学报, 2016 , 52(9) : 1070 -1078 . DOI: 10.11900/0412.1961.2016.00019
Ti2AlNb alloys are considered as a potential structural material for high temperature applications like gas turbine engine components due to their high specific strength and good creep resistance. In this work, pre-alloyed powder of Ti-22Al-24Nb-0.5Mo (atomic fraction, %) was prepared by an electrode induction melting gas atomization process and powder metallurgy (PM) alloys was made through a hot isostatic pressing (HIPing) route. PM Ti-22Al-24Nb-0.5Mo rings and plates were welded by electron beam welding (EBW). The microstructure of the welded joints was investigated by OM, SEM, EPMA and X-ray tomography. The effect of post-weld heat treatments (PWHT) on the microhardness, tensile properties and rupture lifetime at 650 ℃, 360 MPa of the welding joint of PM Ti-22Al-24Nb-0.5Mo plate was also studied. The results show that the HIPing temperature will affect the porosity distribution of PM Ti-22Al-24Nb-0.5Mo alloys. The PM Ti-22Al-24Nb-0.5Mo rings HIPed at 1030 ℃ after 980 ℃, 2 h, vacuum furnace cooling show good weldability. The fusion zone (FZ), heat affected zone (HAZ) and base metal (BM) of welded joints show homogeneous chemical composition. The microstructures of FZ, HAZ and BM are different while the microhardnesses of FZ, HAZ and BM show no obvious differences. Tensile and stress rupture lifetime testing specimens all fracture in the FZ. It is found that there are a certain number of micro-porosity in the FZ of the welded joints. However, the porosity reduces after PWHT, which will improve the high temperature ductility and rupture properties of the PM Ti-22Al-24Nb-0.5Mo welded joints.
| [1] | Banerjee D, Gogia A K, Nandi T K, Joshi V A.Acta Metall, 1988; 36: 871 |
| [2] | Wang Z, Cao L, Liu R C, Liu D, Cui Y Y, Yang R.Acta Metall Sin, 2013; 49: 1487 |
| [2] | (王震, 曹磊, 刘仁慈, 刘冬, 崔玉友, 杨锐. 金属学报, 2013, 49: 1487) |
| [3] | Boehlert C J, Majumdar B S, Seetharaman V, Miracle D B.Metall Mater Trans, 1999; 30A: 2305 |
| [4] | Zhang S Z.PhD Dissertation, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 2004 |
| [4] | (张尚洲. 中国科学院金属研究所博士学位论文, 沈阳, 2004) |
| [5] | Hu D, Wu X, Loretto M H.Intermetallics, 2005; 13: 914 |
| [6] | Wang Y.PhD Dissertation, Institute of Metal Research, Chinese Academy of Sciences, Shenyang, 2011 |
| [6] | (王永. 中国科学院金属研究所博士学位论文, 沈阳, 2011) |
| [7] | Yang R.Acta Metall Sin, 2015; 51: 129 |
| [7] | (杨锐. 金属学报, 2015; 51: 129) |
| [8] | Wegmann G, Gerling R, Schimansky F P.Acta Mater, 2003; 51: 741 |
| [9] | Wu J, Xu L, Lu B, Cui Y Y, Yang R.Chin J Mater Res, 2014; 28: 387 |
| [9] | (吴杰, 徐磊, 卢斌, 崔玉友, 杨锐. 材料研究学报, 2014; 28: 387) |
| [10] | Rao K P, Prasad Y V R K, Suresh K.Mater Des, 2011; 32: 4874 |
| [11] | Wu J, Xu L, Lu Z G, Lu B, Cui Y Y, Yang R.J Mater Sci Technol, 2015; 31: 1251 |
| [12] | Wang G, Xu L, Tian Y X, Zheng Z, Cui Y Y, Yang R.Mater Sci Eng, 2011; A528: 6754 |
| [13] | Chen Z Y, Wang Q J, Liu J R, Li Y L, Yang R, Li J W, Liu F J.Acta Metall Sin, 2008; 44: 263 |
| [13] | (陈志勇, 王清江, 刘建荣, 李玉兰, 杨锐, 李晋炜, 刘方军. 金属学报, 2008; 44: 263) |
| [14] | Deng Y H, Guan Q, Tao J, Wu B, Wang X C.Acta Metall Sin, 2015; 51: 1111 |
| [14] | (邓云华, 关桥, 陶军, 吴冰, 王西昌. 金属学报, 2015; 51: 1111) |
| [15] | Guo R P. Master Thesis, Northeastern University, Shenyang, 2014 |
| [15] | (郭瑞鹏. 东北大学硕士学位论文, 沈阳, 2014) |
| [16] | Guo R P, Xu L, Wu J, Yang R, Zong B Y. Mater Sci Eng, 2015; A639: 327 |
| [17] | Wang S G, Wang S C, Zhang L.Acta Metall Sin, 2013; 49: 897 |
| [17] | (王绍钢, 王苏程, 张磊. 金属学报, 2013; 49: 897) |
| [18] | Xu L, Wu J, Cui Y Y, Yang R.In: Kim Y W, Smarsly W, Lin J P, Dimiduk D, Appel F eds., Gamma Titanium Aluminide Alloys 2014, Warrendale, PA: TMS, 2014: 195 |
| [19] | Liu X W, Su Y Q, Luo L S, Li K, Dong F Y, Guo J J, Fu H Z.Int J Hydrogen Energy, 2011; 36: 3260 |
| [20] | Li W B, Easterling K E.Powder Metall, 1992; 35: 47 |
| [21] | Xu L, Guo R P, Bai C G, Lei J F, Yang R.J Mater Sci Technol, 2014; 30: 1289 |
| [22] | Wu J, Xu L, Guo R P, Lu Z G, Cui Y Y, Yang R.Mater Res Innovations, 2015; 19(sup9): 46 |
| [23] | Kou S. WeldingMetallurgy.2nd ed . Canada: John Wiley &Sons, 2003: 27 |
| [24] | Boehlert C J.Metall Mater Trans, 2001; 32A: 1977 |
| [25] | Boehlert C J, Miracle D B.Metall Mater Trans, 1999; 30A: 2349 |
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| 〈 |
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〉 |
