Impact Welding of Aluminum Alloys 6061 and 5052 by Vaporizing Foil Actuators: Heat-Affected Zone Size and Peel Strength

Abstract

Joining aluminum alloy sheets is increasingly important in manufacturing. Traditional welding techniques create a heat-affected zone (HAZ) around the joint; however, solid-state joining methods such as impact welding produce joints without significant heat. Here, electrically vaporized foil actuators (VFA) provided the high-pressure pulses needed for impact welding. 0.96 mm thick AA6061-T6 and 0.76 mm thick AA5052 were joined in lap and spotlike configurations, at a variety of impact velocities. The welds failed in coach-peel outside the joint interface. The 5052 hardened within 100 μm of the interface. The 6061-T6 may have softened slightly within 50 μm of the interface.

Dissimilar Materials Welding with a Standoff-Free Vaporizing Foil Actuator between TRIP 1180 Steel Sheets and AA5052 Alloy

“…To guarantee the uniform contact pressure in between specimens and experimental safety against explosive pressure during the VFAW test, the top and bottom surface of the stacked specimens are tightened by a back-up die set. In addition, Kapton film has been utilized to insulate the Al foil from the die set and the other welding specimens, which tends to prevent a current loss [23]. After an initial set-up, a target current from the capacitor bank directly flows to the Al foil through the copper plate as shown in sheet and an AA5052 sheet.…”

“…To guarantee the uniform contact pressure in between specimens and experimental safety against explosive pressure during the VFAW test, the top and bottom surface of the stacked specimens are tightened by a back-up die set. In addition, Kapton film has been utilized to insulate the Al foil from the die set and the other welding specimens, which tends to prevent a current loss [23]. After an initial set-up, a target current from the capacitor bank directly flows to the Al foil through the copper plate as shown in Figure 4 To demonstrate practical welding between GPa grade steel and Al alloy, TRIP1180 and AA5052-H32 sheets with a length, width, and thickness of 100 mm × 50 mm × 1.2 mm, and 200 mm × 50 mm × 1.0 mm, respectively, have been applied to the VFAW process as a target and flyer sheet, respectively.…”

“…To secure a sufficient flying distance, the TRIP1180 target sheet with a thickness of 1.2 mm has been stamped to have an indentation along the circular boundary as depicted in Figure 7, which is applied to the initial stacking for the standoff-free VFAW test. The preform die set is designed to impress a circular indentation [32] on the target sheet with a diameter and height of 30 mm and 1.6 mm since it has been validated in the conventional VFAW experiments [23][24][25]29,30] for guaranteeing the optimum welding area and flying distance. The design variables in the specification of the die set are represented in Figure 8.…”

“…The vaporizing foil actuator welding (VFAW) is the one of the explosion welding, which does not involve the conventional full melting of the materials being joined. It applies substantially high pressure to the bottom of a flyer sheet as depicted in Figure 1a to make it collide with a target sheet, which tends to induce metallic bonding [22][23][24] at the interface for permanent welding. When a high current is instantly applied to the aluminum foil, it is vaporized from solid to gas, directly, which tends to generate tremendously high pressure as shown in Figure 1b.…”

Process Optimization of Cold Metal Transfer Plug Welding of Aluminum AA6061-T6-to-Galvanized DP590 Steel Based on Orthogonal Experiment Method

“…In order to improve the power performance of the car, reduce fuel consumption and exhaust pollution, lightweight of automobile has become an inevitable development trend of automobile manufacturing [1]. The application of aluminum steel joining structure is one of the important methods to realize the lightweight of automobile body nowadays [2].…”