Effect of post weld heat treatment on microstructure and fracture toughness of friction welded joint

Abstract

The effect of post weld heat treatment on the microstructure and fracture toughness of friction welded joints of Ti-6.5Al-1Mo-1V-2Zr alloy was studied. The experimental results show that equiaxial grains were formed at the center of the weld metal while highly deformed grains were observed in the thermomechanically affected zone. The fracture toughness of the weld metal was lower than that of the thermomechanically affected zone under as-weld and post weld heat treatment conditions. With increasing temperature of post weld heat treatment, the fracture toughness of weld center and thermomechanically affected zone increased. The fractographic observation revealed that the friction welded joints fractured in a ductile mode.

Keywords

titanium alloy / post weld heat treatment / microstructure / fracture toughness

References

[1] Wang Y, Zhu JC, Lai ZH, et al. Hot Compressive Deformation Behaviour and Microstructural Variation of TA15 Titanium Alloy[J]. Material Science And Technology, 2005, 21: 1466-1470.

[2] Sun ZC, Yang H. Microstructure and Mechanical Properties of TA15 Titanium Alloy under Multi-step Local Loading Forming[J]. Materials Science and Engineering A, 2009, 523: 184-192.

[3] Cao JX, Fang B, Huang X, et al. Effects of Microstructure on Properties of TA15 Titanium Alloy[J]. Chinese Journal of Rare Metals, 2004, 28(2): 362-364.

[4] Sun QJ, Wang GG. Microstructure and Superplasticity of TA15 Alloy[J]. Materials Science and Engineering A, 2014, 606: 401-408.

[5] Shtrikman MM. Linear Friction Welding[J]. Welding International, 2010, 24(7): 563-569.

[6] Ma TJ, Chen T, Li WY, et al. Formation Mechanism of Linear Friction Welded Ti-6Al-4V Alloy Joint based on Microstructure Observation[J]. Materials Characterization, 2011, 62: 130-135.

[7] Corzo V, Casals O, Alcal J, et al. Mechanical Evaluation of Linear Friction Welds in Titanium Alloys Through Indentation Experiments[J]. Welding International, 2007, 21(2): 125-129.

[8] Wanjara P, Jahazi M. Linear Friction Welding of Ti-6Al-4V: Processing, Microstructure, and Mechanical-property Inter-relationships[J]. Metall Mater. Trans. A, 2005, 36(21): 49-64.

[9] Karadge M, Preuss M, Lovell C, et al. Texture Development in Ti-6Al-4V Linear Friction Welds[J]. Materials Science and Engineering A, 2007, 459: 182-191.

[10] Ji YP, Wu SJ. Study on Microstructure and Mechanical Behavior of Dissimilar Ti17 Friction Welds[J]. Materials Science and Engineering A, 2014, 596: 32-40.

[11] Huang DM, Liu H, Wang XC, et al. Influence of Forging Process on Microstructure and Mechanical Properties of Large Section Ti-6.5Al-1Mo-1V-2Zr Alloy Bars[J]. Tansactions of Nonferrous Metals Society of China, 2013, 23(8): 2276-2282.

[12] Sun QJ, Wang GC, Li MQ. Enhanced the Superplasticity in Ti-6.5Al-2Zr-1Mo-1V Alloy by a Two-step Deformation Method[J]. Materials and Design, 2012, 35: 80-86.

[13] He D, Zhu JC, Lai ZH, et al. An Experimental Study of Deformation Mechanism and Microstructure Evolution during Hot Deformation of Ti-6Al-1Mo-1V-2Zr Alloy[J]. Materials and Design, 2013, 46: 38-48.

[14] Livan F, Gianluca B, Davide C, et al. Investigations on the Linear Friction Welding Process Through Numerical Simulations and Experiments[J]. Materials and Design, 2012, 40: 285-291.

[15] Guo YN, Chiu YL, Moataz MA. Characterization of Dissimilar Linear Friction Welds of α-β Titanium Alloys[J]. ASM International, 2012, 21: 770-776.

[16] Zhang CC, Zhang TC, Ji YJ, et al. Effects of Heat Treatment on Microstructure and Microhardness of Linear Friction Welded Dissimilar Ti Alloys[J]. Transactions of Nonferrous Metals Society of China, 2013, 23(12): 3540-3544.

[17] Li WY, Ma TJ, Li JL. Numerical Simulation of Linear Friction Welding of Titanium Alloy: Effects of Processing Parameters[J]. Materials and Design, 2010, 31: 1497-1507.

[18] Ma TJ, Li WY, Yang SY. Impact Toughness and Fracture Analysis of Linear Friction Welded Ti-6Al-4V Alloy Joints[J]. Materials and Design, 2009, 30: 2128-2132.

[19] Lv YF, Meng XJ, Li SK, et al. Effects of Annealing Heat Treatment on Microstructure and Properties of TA15 Titanium Alloy[J]. Development and Application of Materials, 2009, 24(5): 7-10.

[20] Sharma C, Dwivedi DK, Kumar P. Effect of Post Weld Heat Treatments on Microstructure and Mechanical Properties of Friction Stir Welded Joints of Al-Zn-Mg Alloy AA7039[J]. Materials and Design, 2013, 43(1): 34-43.

[21] Keshava K, Murthy S. Effect of Microstructure Features on the Fracture Toughness of a Welded Alpha-beta Ti-Al-Mn Alloy[J]. Engineering Fracture Mechanics, 1997, 2(58): 29-41.