ABSTRACT
Innovation and improvement of technologies are crucial to the economic growth of the world’s leading countries in all segments. Aluminum (Al) and Titanium (Ti) alloys are the leading materials used to make lightweight structural components for their high fracture toughness, good strength-to-weight ratio, and anti-corrosion properties. Considering the energy consumption rate, Ultrasonic Welding (USW) technology is a proven solid-phase bonding method to produce high-integrity joints at a minimal time. This rapid joining technique creates a solid-state bond between the two pieces of metals, using high-frequency ultrasonic energy. This parametric study comprehensively investigates the USW of Al-Ti joints through various weld conditions. The influence of weld parameters on the bond line is studied through mechanical performance and microstructural characterization. The value of tensile-shear strength increases as the weld time increases, and then decreases as the weld time continues to increase due to the occurrence of fatigue cracks on the surface of Al. The weld surface of Al alloy is softened by the end of welding, while the micro-hardness value of Ti alloy doesn’t change noticeably. The microstructural characteristic is analyzed on the weld interface through Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy (EDS). The X-ray Diffraction (XRD) analysis results disclosed that no visible amount of intermetallic reaction layer is developed in Al-Ti joints, which is also ascertained by Transmission Electron Microscopy (TEM).
