Optimized welding parameters for Al 6061 ultrasonic additive manufactured structures

Abstract

Ultrasonic additive manufacturing (UAM) is a solid state manufacturing process that combines additive joining of thin metal tapes and subtractive computer numerical control milling operations to generate near-net shape metallic parts. We conducted a design of experiments study with the goal to optimize UAM process parameters for aluminum 6061. Weld force, weld speed, amplitude, and temperature were varied based on a Taguchi L18 experimental design matrix and tested for mechanical strength using a shear test and a comparative push-pin test. Statistical methods including analysis of variance (ANOVA), mean effects plots, and interaction effects plots were conducted to determine optimal process parameters. Results indicate that weld amplitudes of 32.76 lm and weld speeds of 84.6 mm/s yield maximum mechanical strength while temperature and force are statistically insignificant for the parameter levels tested. Annealing of cold-worked foil stock produces a 13% strength increase for UAM samples over homogeneous annealed material.

Effect of post weld heat treatment on the 6061 aluminum alloy produced by ultrasonic additive manufacturing

“…Ultrasonic additive manufacturing (UAM) is a solid state hybrid manufacturing process that uses high-frequency (usually 20 kHz) ultrasonic vibrations to fabricate parts in a layered manner [1,2]. Compared to traditional industrial technologies, UAM allows for complex shaped parts with internal channels or cavities [1] and has the ability to fabricate fully functional hybrid materials.…”

Characterization of embedded fiber optic strain sensors into metallic structures via ultrasonic additive manufacturing

“…Several fabrication parameters impact the performance of embedded FBGs, including the amplitude, speed, and down force on the sonotrode. 10,14 Samples were built using 0.154 mm (6 mil) thick foil, 4000 N down force, ultrasonic amplitude of 32 microns, and a weld speed of 508 cm/min (200 in/min). Two to three layers of foil were welded onto an aluminum baseplate prior to embedment of the fiber, to ensure consistent properties of the matrix material surrounding the fiber.…”

Deformation Mechanisms in NiTi-Al Composites Fabricated by Ultrasonic Additive Manufacturing

“…All welding was performed at room temperature (22°C) rather than elevated temperature to avoid sample overheating during fabrication. These welding parameters, which were adopted from a recent design-of-experiments study to optimize the welding parameters of Al 6061-H18 [30], been shown to be sufficient in pilot NiTi-Al welds. The fibers were prestressed up to 580 MPa, unloaded as described earlier, and then placed in the channels for UAM welding.…”