Zahabi Saeed, Mohammad Sharifi Ehsan, Naderi Mehdi, Ramezani Mazaher, Jamali Hossein, Loghman Esatrki Mohammad Reza
Department of Materials Engineering, Malek Ashtar University of Technology, Isfahan, Iran.
Heliyon. 2024 Mar 3;10(6):e27514. doi: 10.1016/j.heliyon.2024.e27514. eCollection 2024 Mar 30.
The welding ability of Ti-6Al-4V alloy is weak due to their two-phase microstructure. On the other hand, friction welding methods lead to significant microstructural changes. In this research, for the first time, pure titanium was successfully joined to the Ti-6Al-4V alloy, without any change in the microstructure and mechanical properties of both alloys, by applying the SPW method. Further, the effects of temperature, pressure, and time of the SPW process on the microstructure and mechanical properties of commercial pure (C.P) titanium joined to the Ti-6Al-4V alloy were investigated. The results indicated that the effect of temperature and pressure on the SPW process was greater than that of time. Further, mechanical properties investigations showed that the yield strength of the joint interface was larger than that of the substrate metal, following which necking and fracture occurred in the pure titanium substrate metal. The alloy (Ti-Ti64) bonded at 800 °C, with a time of 10 min and pressure of 20 MPa, exhibited the superior bonding of 7-9 μm interface thickness, and excellent tensile strength (534 ± 13 MPa) and Vickers micro-hardness (190 ± 5 HV). Investigation of the effect of pressure (normal stress) also showed that with an increase in pressure, because of the reduction of the chemical potential of diffusing species, the joint temperature would drop, and the joint could be created at a temperature below 800 °C.
Ti-6Al-4V合金由于其两相微观结构，焊接能力较弱。另一方面，摩擦焊接方法会导致显著的微观结构变化。在本研究中，首次通过应用搅拌摩擦点焊（SPW）方法，成功将纯钛与Ti-6Al-4V合金连接起来，且两种合金的微观结构和力学性能均未发生任何变化。此外，还研究了SPW工艺的温度、压力和时间对与Ti-6Al-4V合金连接的工业纯（C.P）钛的微观结构和力学性能的影响。结果表明，温度和压力对SPW工艺的影响大于时间。此外，力学性能研究表明，接头界面的屈服强度大于基体金属的屈服强度，随后纯钛基体金属发生颈缩和断裂。在800℃、时间为10分钟、压力为20MPa的条件下结合的合金（Ti-Ti64），表现出7-9μm的优异界面厚度结合、出色的拉伸强度（534±13MPa）和维氏显微硬度（190±5HV）。对压力（法向应力）影响的研究还表明，随着压力的增加，由于扩散物种化学势的降低，接头温度会下降，并且接头可以在低于800℃的温度下形成。
