Please wait a minute...
Acta Metall Sin  2019, Vol. 55 Issue (5): 611-618    DOI: 10.11900/0412.1961.2018.00504
Current Issue | Archive | Adv Search |
Microstructural Evolution and Mechanism of Solidified TiAl Alloy Applied Electric Current Pulse
Zhanxing CHEN,Hongsheng DING(),Ruirun CHEN,Jingjie GUO,Hengzhi FU
1. National Key Laboratory for Precision Hot Processing of Metals, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Download:  HTML  PDF(15521KB) 
Export:  BibTeX | EndNote (RIS)      
Abstract  

As a new type of lightweight and high temperature structural material, TiAl alloy has become the most ideal candidate in the fields of aerospace, military and civil products, and it has a good perspective in the industrialization. Refining and improving the microstructure of TiAl alloys has higher theoretical significance and engineering value. In this work, the solidified Ti-48Al-2Cr-2Nb alloy applied electric current pulse is studied, and its microstructural evolution and mechanism are analyzed. The results show that the electric current pulse refines the primary dendrite arm spacing, columnar crystal size and interlamellar spacing of the Ti-48Al-2Cr-2Nb alloy. The primary phase is α without electric current pulse, the angle of the Ti-48Al-2Cr-2Nb alloy that between the lamellar orientation and the growth direction is usually bigger, even perpendicular to the growth direction approximately. The applied electric current pulse causes the dendrite to melt and break, and promotes the occurrence and increase of the primary β phase, the lamellae orientation having a small angle or 45° between the growth direction is further increasing. The electric current pulse reduces the solid-liquid phase free energy and atomic diffusion activation energy, reduces the nucleation barrier and the critical nucleation energy, thereby atomic diffusion and the crystallization nucleation is promoted to a certain extent, the primary dendritic spacing and columnar crystals are remarkably refined. The electric current pulse causes the transformation of the primary phase and its corresponding crystal orientation relationship is the main reason for the change of lamellar orientation.

Key words:  electric current pulse      TiAl alloy      microstructural evolution      lamellar orientation     
Received:  07 November 2018     
ZTFLH:  TG113.12  
Fund: National Natural Science Foundation of China(51171053);National Natural Science Foundation of China(51471062);National Natural Science Foundation of China(51671072)
Corresponding Authors:  Hongsheng DING     E-mail:  dinghsh@hit.edu.cn

Cite this article: 

Zhanxing CHEN,Hongsheng DING,Ruirun CHEN,Jingjie GUO,Hengzhi FU. Microstructural Evolution and Mechanism of Solidified TiAl Alloy Applied Electric Current Pulse. Acta Metall Sin, 2019, 55(5): 611-618.

URL: 

https://www.ams.org.cn/EN/10.11900/0412.1961.2018.00504     OR     https://www.ams.org.cn/EN/Y2019/V55/I5/611

Sample No.ip / (mA·mm-2)f / Hz
10-
232100
364100
496100
56450
664200
Table 1  Parameters of electric current pulse acting on Ti-48Al-2Cr-2Nb alloy
Fig.1  Dendritic morphologies of Ti-48Al-2Cr-2Nb alloy with electric current pulse(a) no current (b) 32 mA/mm2, 100 Hz (c) 64 mA/mm2, 100 Hz(d) 96 mA/mm2, 100 Hz (e) 64 mA/mm2, 50 Hz (f) 64 mA/mm2, 200 Hz
Fig.2  Primary dendritic arm spacing (PDAS) of Ti-48Al-2Cr-2Nb alloy affected by current density (frequency is 100 Hz) (a) and frequency (current density is 64 mA/mm2) (b)
Fig.3  Microstructures of solidified Ti-48Al-2Cr-2Nb alloy with electric current pulse(a) no current (b) 32 mA/mm2, 100 Hz (c) 64 mA/mm2, 100 Hz(d) 96 mA/mm2, 100 Hz (e) 64 mA/mm2, 50 Hz (f) 64 mA/mm2, 200 Hz
Fig.4  Normal frequency distributions of lamellar orientation for solidified Ti-48Al-2Cr-2Nb alloy with different parameters of electric current pulse
Fig.5  Lamellar structures of Ti-48Al-2Cr-2Nb alloy solidified with electric current pulse(a) no current (b) 32 mA/mm2, 100 Hz (c) 64 mA/mm2, 100 Hz(d) 96 mA/mm2, 100 Hz (e) 64 mA/mm2, 50 Hz (f) 64 mA/mm2, 200 Hz
Fig.6  Interlamellar spacing of solidified Ti-48Al-2Cr-2Nb alloy affected by current density (frequency is 100 Hz) (a) and frequency (current density is 64 mA/mm2) (b)
Fig.7  Schematics of the relationship between the lamellar orientation and the growth direction of different primary phasesColor online(a) crystal orientation and lamellar orientation of α phase (b) crystal orientation and lamellar orientation of β phase
[1] AsaiS. Recent development and prospect of electromagnetic processing of materials[J]. Sci. Technol. Adv. Mater., 2000, 1: 191
[2] AsaiS. Electromagnetic Processing of Materials[M]. Dordrecht: Springer, 2012: 87
[3] WangR Z, QiJ G, WangB, et al. Solidification behavior and crystal growth mechanism of aluminum under electric pulse[J]. J. Mater. Process. Technol., 2016, 237: 235
[4] TangY F, QiuS, MiaoQ, et al. Fabrication of lamellar porous alumina with axisymmetric structure by directional solidification with applied electric and magnetic fields[J]. J. Eur. Ceram. Soc., 2016, 36: 1233
[5] LiC S, HuS D, RenZ M, et al. Effect of the simultaneous application of a high static magnetic field and a low alternating current on grain structure and grain boundary of pure aluminum[J]. J. Mater. Sci. Technol., 2018, 34: 2431
[6] LiY Z, Mangelinck-No?lN, ZimmermannG, et al. Effect of solidification conditions and surface pores on the microstructure and columnar-to-equiaxed transition in solidification under microgravity[J]. J. Alloys Compd., 2018, 749: 344
[7] RuanY, WangQ Q, ChangS Y, et al. Structural evolution and micromechanical properties of ternary Al-Ag-Ge alloy solidified under microgravity condition[J]. Acta Mater., 2017, 141: 456
[8] XuanY, NastacL. The role of ultrasonic cavitation in refining the microstructure of aluminum based nanocomposites during the solidification process[J]. Ultrasonics, 2018, 83: 94
[9] ChenZ X, DingH S, ChenR R, et al. An innovative method for the microstructural modification of TiAl alloy solidified via direct electric current application[J]. J. Mater. Sci. Technol., 2019, 35: 23
[10] LiJ, MaJ H, SongC J, et al. Columnar to equiaxed transition during solidification of small ingot by using electric current pulse[J]. J. Iron Steel Res., Int., 2009, 16: 7
[11] LiJ Y, NiP, WangL, et al. Influence of direct electric current on solidification process of Al-Si alloy[J]. Mater. Sci. Semicond. Process., 2017, 61: 79
[12] YangJ R, ChenR R, GuoJ J, et al. Temperature distribution in bottomless electromagnetic cold crucible applied to directional solidification[J]. Int. J. Heat Mass Transfer, 2016, 100: 131
[13] YangJ R, ChenR R, SuY Q, et al. Optimization of electromagnetic energy in cold crucible used for directional solidification of TiAl alloy[J]. Energy, 2018, 161: 143
[14] ErdelyP, StaronP, MaawadE, et al. Design and control of microstructure and texture by thermomechanical processing of a multi-phase TiAl alloy[J]. Mater. Des., 2017, 131: 286
[15] WangX D, LuoR C, LiuF, et al. Characterization of Gd-rich precipitates in a fully lamellar TiAl alloy[J]. Scr. Mater., 2017, 137: 50
[16] ZhangT B, WuZ E, HuR, et al. Influence of nitrogen on the microstructure and solidification behavior of high Nb containing TiAl alloys[J]. Mater. Des., 2016, 103: 100
[17] ZollingerJ, LapinJ, DalozD, et al. Influence of oxygen on solidification behaviour of cast TiAl-based alloys[J]. Intermetallics, 2007, 15: 1343
[18] JungI S, JangH S, OhM H, et al. Microstructure control of TiAl alloys containing β stabilizers by directional solidification[J]. Mater. Sci. Eng., 2002, A329-331: 13
[19] ChenZ X, DingH S, LiuS Q, et al. Effects of direct current on microstructure and properties of Ti-48Al-2Cr-2Nb alloy[J].Acta Metall. Sin., 2017, 53: 583
[19] (陈占兴, 丁宏升, 刘石球等. 直流电流对Ti-48Al-2Cr-2Nb合金组织和性能的影响 [J]. 金属学报, 2017, 53: 583)
[20] LiX Z, FanJ L, SuY Q, et al. Lamellar orientation and growth direction of α phase in directionally solidified Ti-46Al-0.5W-0.5Si alloy[J]. Intermetallics, 2012, 27: 38
[21] BarnakJ P, SprecherA F, ConradH. Colony (grain) size reduction in eutectic Pb-Sn castings by electroplusing[J]. Scr. Metall. Mater., 1995, 32: 879
[22] ZhaiQ J. Foundamentals of Structure Refinement Technology for Metal Solidification[M]. Beijing: Science Press, 2018: 145
[22] (翟启杰. 金属凝固组织细化技术基础 [M]. 北京: 科学出版社, 2018: 145)
[23] GaoM, HeG H, YangF, et al. Effect of electric current pulse on tensile strength and elongation of casting ZA27 alloy[J]. Mater. Sci. Eng., 2002, A337: 110
[24] NakadaM, ShioharaY, FlemingsM C. Modification of solidification structures by pulse electric discharging[J]. ISIJ Int., 1990, 30: 27
[25] ZhangW, SuiM L, ZhouY Z, et al. Electropulsing-induced evolution of microstructures in materials[J].Acta Metall. Sin., 2003, 39: 1009
[25] (张 伟, 隋曼龄, 周亦胄等. 高密度电脉冲下材料微观结构的演变 [J]. 金属学报, 2003, 39: 1009)
[26] TangJ C, HuangB Y, ZhouK C, et al. Factors affecting the lamellar spacing in two-phase TiAl alloys with fully lamellar microstructures[J]. Mater. Res. Bull., 2001, 36: 1737
[27] LapinJ, Ondrú?L', NazmyM. Directional solidification of intermetallic Ti-46Al-2W-0.5Si alloy in alumina moulds[J]. Intermetallics, 2002, 10: 1019
[28] ClemensH, BartelsA, BystrzanowskiS, et al. Grain refinement in γ-TiAl-based alloys by solid state phase transformations[J]. Intermetallics, 2006, 14: 1380
[29] InuiH, OhM H, NakamuraA, et al. Room-temperature tensile deformation of polysynthetically twinned (PST) crystals of TiAl[J]. Acta Metall. Mater., 1992, 40: 3095
[30] JungI S, OhM H, ParkN J, et al. Lamellar boundary alignment of DS-processed TiAl-W alloys by a solidification procedure[J]. Met. Mater. Int., 2007, 13: 455
[1] WANG Xi,LIU Renci,CAO Ruxin,JIA Qing,CUI Yuyou,YANG Rui. Effect of Cooling Rate on Boride and Room Temperature Tensile Properties of β-Solidifying γ-TiAl Alloys[J]. 金属学报, 2020, 56(2): 203-211.
[2] WU Jing,LIU Yongchang,LI Chong,WU Yuting,XIA Xingchuan,LI Huijun. Recent Progress of Microstructure Evolution and Performance of Multiphase Ni3Al-Based Intermetallic Alloy with High Fe and Cr Contents[J]. 金属学报, 2020, 56(1): 21-35.
[3] Yimin LIAO, Min FENG, Minghui CHEN, Zhe GENG, Yang LIU, Fuhui WANG, Shenglong ZHU. Comparative Study of Hot Corrosion Behavior of theEnamel Based Composite Coatings and the ArcIon Plating NiCrAlY on TiAl Alloy[J]. 金属学报, 2019, 55(2): 229-237.
[4] JIN Hao, JIA Qing, LIU Ronghua, XIAN Quangang, CUI Yuyou, XU Dongsheng, YANG Rui. Seed Preparation and Orientation Control of PST Crystals of Ti-47Al Alloy[J]. 金属学报, 2019, 55(12): 1519-1526.
[5] Yanqing SU, Tong LIU, Xinzhong LI, Ruirun CHEN, Jingjie GUO, Hengzhi FU. The Evolution of Seeding Technique for the Lamellar Orientation Controlling of γ-TiAl Based Alloys[J]. 金属学报, 2018, 54(5): 647-656.
[6] Yu PAN, Xin LU, Chengcheng LIU, Jianzhuo SUN, Jianbo TONG, Wei XU, Xuanhui QU. Effect of Sn Addition on Densification and Mechanical Properties of Sintered TiAl Base Alloys[J]. 金属学报, 2018, 54(1): 93-99.
[7] Tianrui LI, Guohuai LIU, Mang XU, Hongzhi NIU, Tianliang FU, Zhaodong WANG, Guodong WANG. Microstructures and High Temperature Tensile Properties of Ti-43Al-4Nb-1.5Mo Alloy in the Canned Forging andHeat Treatment Process[J]. 金属学报, 2017, 53(9): 1055-1064.
[8] Zhanxing CHEN,Hongsheng DING,Shiqiu LIU,Ruirun CHEN,Jingjie GUO,Hengzhi FU. Effects of Direct Current on Microstructure and Properties of Ti-48Al-2Cr-2Nb Alloy[J]. 金属学报, 2017, 53(5): 583-591.
[9] Gang WANG,Lei XU,Yuyou CUI,Rui YANG. DENSIFICATION MECHANISM OF TiAl PRE-ALLOY POWDERS CONSOLIDATED BY HOT ISOSTATIC PRESSING AND EFFECTS OF HEAT TREATMENTON THE MICROSTRUCTURE OF TiAl POWDER COMPACTS[J]. 金属学报, 2016, 52(9): 1079-1088.
[10] Junjun CUI,Liqing CHEN,Haizhi LI,Weiping TONG. TEMPERED MICROSTRUCTURE AND MECHANICAL PROPERTIES OF AUSTEMPERED LOW ALLOYED BAINITIC DUCTILE IRON[J]. 金属学报, 2016, 52(7): 778-786.
[11] Liang YANG,Shubo GAO,Yanli WANG,Teng YE,Lin SONG,Junpin LIN. EFFECT OF Si ADDITION ON THE MICROSTRUCTURE AND ROOM TEMPERATURE TENSILE PROPERTIES OF HIGH Nb-TiAl ALLOY[J]. 金属学报, 2015, 51(7): 859-865.
[12] SUN Wen, QIN Xuezhi, GUO Jianting, LOU Langhong, ZHOU Lanzhang. EFFECTS OF (W+Mo)/Cr RATIO ON MICROSTRUC-TURAL EVOLUTIONS AND MECHANICAL PROPER-TIES OF CAST Ni-BASED SUPERALLOYS DURING LONG-TERM THERMAL EXPOSURE[J]. 金属学报, 2015, 51(1): 67-76.
[13] FU Mingjie, HAN Xiuquan, WU Wei, ZHANG Jianwei. SUPERPLASTICITY RESEARCH OF Ti-23Al-17Nb ALLOY SHEET[J]. 金属学报, 2014, 50(8): 955-961.
[14] ZHOU Huan, ZHANG Tiebang, WU Zeen, HU Rui, KOU Hongchao, LI Jinshan. FORMATION AND EVOLUTION OF PRECIPITATE IN TiAl ALLOY WITH ADDITION OF INTERSTITIAL CARBON ATOM[J]. 金属学报, 2014, 50(7): 832-838.
[15] SUN Wen, QIN Xuezhi, GUO Yongan, GUO Jianting, LOU Langhong, ZHOU Lanzhang. EFFECTS OF Nb/Ti RATIOS ON THE MICROSTRUCTURAL EVOLUTIONS OF CAST Ni-BASED SUPERALLOYS DURING LONG-TERM THERMAL EXPOSURE[J]. 金属学报, 2014, 50(6): 744-752.
No Suggested Reading articles found!