电铝热还原法制备的钛铝合金真空磁悬浮精炼研究
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摘要
真空磁悬浮精炼TiAl合金理论及试验研究表明:提高真空度和增大加热电流有利于降低合金中氧含量,但是Al元素挥发严重,精炼过程剧烈,不利于合金成分控制和渣夹杂物去除。加热电流60 A,真空度400 Pa(通入氩气),精炼时间30 min条件下,合金中大颗粒的渣夹杂物得到有效去除,相同工艺条件下,精炼两次后,合金中O含量降低到0.50%,N含量降低到0.55%。精炼两次后得到的TiAl合金的组织为近层片组织,由γ和α_2组织构成,主要物相由TiAl、Ti_2AlN和Ti_2Al相组成,得到了目标TiAl合金的微观组织和相组成。该工艺制备的TiAl合金为室温脆性断裂,弯曲强度为258 MPa,维氏硬度(HV)为486。
The theory and experiment results for vacuum magnetic levitation refining of titanium aluminum alloy(TiAl alloy) indicate that increasing the vacuum degree and heating current can help to decrease the oxygen content in the alloy,while it suffers from Al volatilization with a drastic process which is adverse to composition control and inclusion removal for the alloy.At heating current of 60 A,vacuum degree of 400 Pa with Ar and refining time of 30 min,the slag inclusions of coarse particle can be effectively removed.After two times of refining at the same conditions,the oxygen and nitrogen content of the alloy can be decreased to 0.50% and 0.55%,respectively.The microstructure of TiAl alloy after two times of refining is near layer tissue composed of γ and α_2 structures,with TiAl,Ti_2AlN and Ti_2Al as the main phases.Brittle fracture at room temperature can be attributed to the obtained alloy,with bending strength of 258 MPa and vickers hardness of 486.
The theory and experiment results for vacuum magnetic levitation refining of titanium aluminum alloy(TiAl alloy) indicate that increasing the vacuum degree and heating current can help to decrease the oxygen content in the alloy,while it suffers from Al volatilization with a drastic process which is adverse to composition control and inclusion removal for the alloy.At heating current of 60 A,vacuum degree of 400 Pa with Ar and refining time of 30 min,the slag inclusions of coarse particle can be effectively removed.After two times of refining at the same conditions,the oxygen and nitrogen content of the alloy can be decreased to 0.50% and 0.55%,respectively.The microstructure of TiAl alloy after two times of refining is near layer tissue composed of γ and α_2 structures,with TiAl,Ti_2AlN and Ti_2Al as the main phases.Brittle fracture at room temperature can be attributed to the obtained alloy,with bending strength of 258 MPa and vickers hardness of 486.
引文
[1] Peng Chaoqun,Huang Boyun,He Yuehui.Effects of rapid heating cyclic heat treatment on microstructures and compression mechanical properties of TiAl-based alloy[J].Transactions of Nonferrous Metals Society of China,2004,14(3):459-463.
[2] Kong Fantao,Chen Ziyong,Tian Jing,et al.Methods of improving room temperature ductility of TiAl based alloys[J].Rare Metal Materials & Engineering,2003,32(2):82-86.
[3] Wang Haiyan,Hu Qianku,Yang Wenpen,et al.Influence of metal element doping on the mechanical properties of TiAl alloy[J]Acta Physica Sinica,2016,65(7):256-264.(王海燕,胡前库,杨文朋,等.金属元素掺杂对TiAl合金力学性能的影响[J].物理学报,2016,65(7):256-264.)
[4] Tang Shouqiao,Qu Shoujiang,Feng Aihan,et al.Research progress in high-temperature oxidation resistance of TiAl-based alloys[J].Chinese Journal of Rare Metals,2017(1):81-93.(汤守巧,曲寿江,冯艾寒,等.TiAl基合金高温抗氧化研究进展[J].稀有金属,2017(1):81-93.)
[5] Wei Y,Zhou H B,Zhang Y,et al.Effects of O in a binary-phase TiAl-Ti3Al alloy:from site occupancy to interfacial energetics[J].Journal of Physics Condensed Matter An Institute of Physics Journal,2011,23(22):225504.
[6] Fan J,Liu J,Wu S,et al.Microstructure formation and interface characteristics of directionally solidified TiAl-Si alloys in alumina crucibles with a new Y2O3 skull-aided technology[J].Scientific Reports,2017,7:45198.
[7] Zhang Xiaoming,Guo Jihong.The preparation of TiAl、TiNi、NiAl intermetallic compound by SHS process[J].Chinese Journal of Rare Metals,1995(4):272-276.(张小明,郭继红.用SHS工艺合成TiAl、TiNi、NiAl金属间化合物[J].稀有金属,1995(4):272-276.)
[8] Farhang M R,Kamali A R,Nazarian-Samani M.Effects of mechanical alloying on the characteristics of a nanocrystalline Ti–50%Al during hot pressing consolidation[J].Materials Science & Engineering B,2010,168(1):136-141.
[9] Zhao K,Wang Y,Feng N.Cleaner production of Ti powder by a two-stage aluminothermic reduction process[J].JOM,2017(4):1-6.
[10] Zhao K,Feng N,Wang Y.Fabrication of Ti-Al intermetallics by a two-stage aluminothermic reduction process using Na2TiF6[J].Intermetallics,2017,85:156-162.
[11] Li Jun,Yang Shaoli,Wu Enhui,et al.Experimental study on preparation of Ti-Al master alloy by aluminothermic reduction of TiO2[J].Iron Steel Vanadium Titanium,2013,34(6):21-24.(李军,杨绍利,吴恩辉,等.铝热还原TiO2制备Ti-Al中间合金试验研究[J].钢铁钒钛,2013,34(6):21-24.)
[12] Li Jun,Lu Xionggang,Yang Shaoli,et al.Theoretical and experimental research on preparation of TiAl alloy by electric aluminothermic reduction[J].Iron Steel Vanadium Titanium,2017,38(5):52-58.(李军,鲁雄刚,杨绍利,等.电铝热还原法制备TiAl合金理论及试验研究[J].钢铁钒钛,2017,38(5):52-58.)
[13] Ren Zhenguo,Cao Zhiqiang.Electromagnetic separation effect of inclusions in Al-melt[J].Materials for Mechanical Engineering,2005,29(10):14-16.(任振国,曹志强.铝熔体内夹杂物电磁分离效果研究[J].机械工程材料,2005,29(10):14-16.)
[14] Shu D,Li T X,Sun B D,et al.Study of electromagnetic separation of nometallic inclusions from aluminum melt[J].Metallurgical & Materials Transactions A,1999,30(11):2979-2988.
[15] Shu Da.Theoretical study on nonmetallic inclusions in electromagnetic separation in aluminum melt[D].Shanghai:Shanghai Jiao Tong University,2000.
[2] Kong Fantao,Chen Ziyong,Tian Jing,et al.Methods of improving room temperature ductility of TiAl based alloys[J].Rare Metal Materials & Engineering,2003,32(2):82-86.
[3] Wang Haiyan,Hu Qianku,Yang Wenpen,et al.Influence of metal element doping on the mechanical properties of TiAl alloy[J]Acta Physica Sinica,2016,65(7):256-264.(王海燕,胡前库,杨文朋,等.金属元素掺杂对TiAl合金力学性能的影响[J].物理学报,2016,65(7):256-264.)
[4] Tang Shouqiao,Qu Shoujiang,Feng Aihan,et al.Research progress in high-temperature oxidation resistance of TiAl-based alloys[J].Chinese Journal of Rare Metals,2017(1):81-93.(汤守巧,曲寿江,冯艾寒,等.TiAl基合金高温抗氧化研究进展[J].稀有金属,2017(1):81-93.)
[5] Wei Y,Zhou H B,Zhang Y,et al.Effects of O in a binary-phase TiAl-Ti3Al alloy:from site occupancy to interfacial energetics[J].Journal of Physics Condensed Matter An Institute of Physics Journal,2011,23(22):225504.
[6] Fan J,Liu J,Wu S,et al.Microstructure formation and interface characteristics of directionally solidified TiAl-Si alloys in alumina crucibles with a new Y2O3 skull-aided technology[J].Scientific Reports,2017,7:45198.
[7] Zhang Xiaoming,Guo Jihong.The preparation of TiAl、TiNi、NiAl intermetallic compound by SHS process[J].Chinese Journal of Rare Metals,1995(4):272-276.(张小明,郭继红.用SHS工艺合成TiAl、TiNi、NiAl金属间化合物[J].稀有金属,1995(4):272-276.)
[8] Farhang M R,Kamali A R,Nazarian-Samani M.Effects of mechanical alloying on the characteristics of a nanocrystalline Ti–50%Al during hot pressing consolidation[J].Materials Science & Engineering B,2010,168(1):136-141.
[9] Zhao K,Wang Y,Feng N.Cleaner production of Ti powder by a two-stage aluminothermic reduction process[J].JOM,2017(4):1-6.
[10] Zhao K,Feng N,Wang Y.Fabrication of Ti-Al intermetallics by a two-stage aluminothermic reduction process using Na2TiF6[J].Intermetallics,2017,85:156-162.
[11] Li Jun,Yang Shaoli,Wu Enhui,et al.Experimental study on preparation of Ti-Al master alloy by aluminothermic reduction of TiO2[J].Iron Steel Vanadium Titanium,2013,34(6):21-24.(李军,杨绍利,吴恩辉,等.铝热还原TiO2制备Ti-Al中间合金试验研究[J].钢铁钒钛,2013,34(6):21-24.)
[12] Li Jun,Lu Xionggang,Yang Shaoli,et al.Theoretical and experimental research on preparation of TiAl alloy by electric aluminothermic reduction[J].Iron Steel Vanadium Titanium,2017,38(5):52-58.(李军,鲁雄刚,杨绍利,等.电铝热还原法制备TiAl合金理论及试验研究[J].钢铁钒钛,2017,38(5):52-58.)
[13] Ren Zhenguo,Cao Zhiqiang.Electromagnetic separation effect of inclusions in Al-melt[J].Materials for Mechanical Engineering,2005,29(10):14-16.(任振国,曹志强.铝熔体内夹杂物电磁分离效果研究[J].机械工程材料,2005,29(10):14-16.)
[14] Shu D,Li T X,Sun B D,et al.Study of electromagnetic separation of nometallic inclusions from aluminum melt[J].Metallurgical & Materials Transactions A,1999,30(11):2979-2988.
[15] Shu Da.Theoretical study on nonmetallic inclusions in electromagnetic separation in aluminum melt[D].Shanghai:Shanghai Jiao Tong University,2000.
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