Enhancing the ultrasonic soldered joint of Cf/Al composite with TC4 alloy by forming a TiAl3 and carbon fiber synergistically reinforcing structures

In this work, carbon fiber reinforced aluminum matrix composite (C f /Al) and TC4 alloy were joined by ultrasonic soldering using ZnAl solder. To reduce the soldering temperature, TC4 alloy was initially hot-dipped in molten pure Al with ultrasonic assistance. Results show that a TiAl 3 particle-reinforced Al layer, 80 μm thick, forms on the TC4 surface after 10 s of ultrasonication and 30 min of holding. During soldering, the Al matrix of both the C f /Al and the TiAl 3 reinforced layer dissolves, exposing the carbon fibers and TiAl 3 particles. These particles and fibers then migrate into the joint under the influence of acoustic vibration and solder squeezing. A fully reinforced joint, synergistically strengthened by both carbon fibers and TiAl 3 particles, is achieved using an ultrasonic power of 1000 W and an ultrasonication time of 12 s. This joint exhibits a shear strength of 30.2 MPa, comparable to the C f /Al substrate. • Soldering temperature was decreased to 420 °C after hot dipping. • TiAl 3 layer forms on TC4 after hot dipping. • Fully TiAl 3 and carbon fiber reinforced joint is obtained at ultrasonication of 12 s and 1000 W. • Joint having strength equal to C f /Al substrate is obtained.