Microstructure and Mechanical Behaviors of Electron Beam Welded Ti44Ni47Nb9 Shape Memory Alloys
The microstructure, martensitic transformation behavior and mechanical properties of the Ti44Ni47Nb9 electron beam welding joints were systemically studied in this research. The results showed that the microstructure of the fusion zone was composed of equiaxed grains with a small quantity of eutectic structure around the grain boundaries, and the grain size in the fusion zone was smaller than that in the as-cast microstructure. The ultimate tensile strength was a little lower than that of the base. The dissolution of niobium in the matrix obstructed the martensite transformation and decreased the martensite start temperature (Ms). After being deformed at the low temperature, the welding joints exhibited good wide transformation hysteresis, which was similar to that of the base metal.
KeywordsTi44Ni47Nb9 shape memory alloys Electron beam welding Martensitic transformation
The authors gratefully acknowledge the financial support for this research provided by the National Natural Science Foundation of China (Grant No. 51001100).
- 1.Xu ZY, Jiang BH (2000) Shape memory materials, Shanghai Jiao Tong PressGoogle Scholar
- 2.Wang L, Yan DS, Jiang ZM, Rong LJ (2004) Research and development of Ti–Ni–Nb shape memory alloy pipe-joint with wide hysteresis. J Mat Eng 7:60–63Google Scholar
- 5.He XM, Rong LJ, Yan DS, Li YY (2006) Deformation dependence of transformation behavior of Ti–Ni–Nb wide hysteresis shape memory alloy. Rare Metal Mat Eng 35(9):227–231Google Scholar
- 6.Cao YH (2000) The development of shape memory alloys and applications in the fields of the missile and aerospace. Winged Missiles J 10:60–63Google Scholar
- 7.Moochul S (2012) Seismic retrofit and repair of reinforced concrete bridge columns using shape memory alloy spirals, Urbana, IllinoisGoogle Scholar
- 9.Wu Y, Meng XL et al (2005) Microstructure and mechanical behaviors of TiNiNb wide hysteresis shape memory alloy wire argon arc welding joint. Mater Sci Technol 13(3):312–319Google Scholar
- 10.Han LJ, Zhao XH, Zhao L, Zhang F (1999) Analysis of welding parameters of precise pulse resistance butt welding on TiNiNb shape memory alloys. Mater Sci Technol 7:76–79Google Scholar
- 11.Chen G, Zhao XK et al (2008) Microstructure and properties of laser welded joint of TiNiNb wide hysteresis shape memory alloy. Hot Work Technol 37(17):99–101Google Scholar
- 12.Liu M, Li YY et al (1997) Influence of precipitates on the two way shape memory effect. Acta Metall Sin 10(3):166–173Google Scholar
- 13.Lu WW, Chen YH et al (2014) Research progress of engineering application and welding technology of new type shape memory alloy of TiNiNb. Aeronaut Manuf Technol (1/2): 94–97Google Scholar