Effects of In-Process Ultrasonic Vibration on Weld Formation and Grain Size of Wire and Arc Additive Manufactured Parts

Abstract

Wire and arc additive manufacturing (WAAM) is a competitive technique, which enables the fabrication of medium and large metallic components. However, due to the presence of coarse columnar grains in the additively manufactured parts, the resultant mechanical properties will be reduced, which limits the application of WAAM processes in the engineering fields. Grain refinement and improved mechanical properties can be achieved by introducing ultrasonic vibration. Herein, we applied ultrasonic vibration to the WAAM process and investigated the effects of wire feed speed, welding speed, and ultrasonic amplitude on the weld formation and grain size during ultrasonic vibration. Finally, a regression model between the average grain size and wire feed speed, welding speed, and ultrasonic amplitude was established. The results showed that due to the difference in heat input and cladding amount, wire feed speed, welding speed, and ultrasonic amplitude have a significant influence on the weld width and reinforcement. Excessive ultrasonic amplitude could cause the weld to crack during spreading. The average grain size increased with increasing wire feed speed and decreasing welding speed. With increasing ultrasonic amplitude, the average grain size exhibited a trend of decreasing first and then increasing. This would be helpful to manufacture parts of the required grain size in ultrasonic vibration-assisted WAAM fields.

Numerical/Experimental Study of Process Optimization Conducted on an Al-Cu Alloy Produced by Combined Fields of Applied Pressure and Ultrasonic Vibration

“…Additionally, to provide a comprehensive comparison between the parts processed under different conditions and to understand the impact of coupled fields on their microstructures, some other samples were also prepared under the conditions of gravity casting, single extrusion pressure, and ultrasonic casting. [20], the metallographic samples were removed from position A, as shown in Figure 1. In this way, the performance of the process under different coupling parameters could be better studied.…”

“…The obtained sample was cut into a size of Φ12 mm × 10 mm. Given that the effects of cavitation and acoustic flow under the ultrasonic vibration are more significant in the local area near the end face of the variable amplitude rod [20], the metallographic samples were removed from position A, as shown in Figure 1. In this way, the performance of the process under different coupling parameters could be better studied.…”

Studying the Effects of Annealing on the Mechanical Properties and Microstructure of Ultrasonic Vibration Welds

“…A study on tungsten inert gas (TIG) and MIG welding with ultrasonic for aluminum alloys revealed that the welding material is refined, porosity reduced, unmixed zones completely eliminated, leading to the enhancement of corrosion resistance in welds [3]. These advantages are related to the introduction of a high-intensity ultrasonic field, which generates two nonlinear effects: cavitation and acoustic streaming [4]. The effects caused by ultrasonic vibrations have mixed materials at the interface between phases in the weld pool.…”