Dynamics of ultrasonic additive manufacturing

Abstract

Ultrasonic additive manufacturing (UAM) is a solid-state technology for joining similar and dissimilar metal foils near room temperature by scrubbing them together with ultrasonic vibrations under pressure. Structural dynamics of the welding assembly and work piece influence how energy is transferred during the process and ultimately, part quality. To understand the effect of structural dynamics during UAM, a linear time-invariant model is proposed to relate the inputs of shear force and electric current to resultant welder velocity and voltage. Measured frequency response and operating performance of the welder under no load is used to identify model parameters. Using this model and in-situ measurements, shear force and welder efficiency are estimated to be near 2000N and 80% when welding Al 6061-H18 weld foil, respectively. Shear force and welder efficiency have never been estimated before in UAM. The influence of processing conditions, i.e., welder amplitude, normal force, and weld speed, on shear force and welder efficiency are investigated. Welder velocity was found to strongly influence the shear force magnitude and efficiency while normal force and weld speed showed little to no influence. The proposed model is used to describe high frequency harmonic content in the velocity response of the welder during welding operations and coupling of the UAM build with the welder.

Complementary Catalysis and Analysis Within Solid-State Additively Manufactured Metal Micro-Flow Reactors

“…Tables Table 1. Ultrasonic additive manufacturing (UAM) processing parameters used for bonding the various Al and Cu material combinations. (Due to the UAM process dynamics, parameters must be adjusted as the height of the part increases to account for an increased height to width ratio 34,35 ). .. 4…”

“…Flow Reactor Fabrication. The device (Figure 1) was achieved using an ultra-high power, 9kW 34,35 ).…”

A comprehensive review of ultrasonic additive manufacturing

“…As a result, there is lack of consensus among the various groups in the joint formation mechanisms. Current models can be categorized as frictional heating from sliding surfaces solely (Yadav and Doumanidis, 2005; Zhang and Li, 2008; Koellhoffer et al , 2011), frictional heating from sliding surfaces and plastic deformation (Siddiq and Ghassemieh, 2009; Siddiq and Sayed, 2012; Kelly et al , 2013; Kelly et al , 2014), frictional heating and junction growth (Mao, 2016; Ward et al , 2018), dislocation accumulation (Kong et al , 2005; Pal and Stucker, 2013), energy input from friction (Yang et al , 2010; Yi et al , 2017), plastic deformation heating (Sriraman et al , 2011) and ultrasonic energy input and microstructure storage (Hehr et al , 2016; Hehr and Dapino, 2017). Some of the modeling efforts use acoustic softening (Siddiq and Ghassemieh, 2009; Siddiq and Sayed, 2012; Kelly et al , 2013; Kelly et al , 2014), which is contested itself as a mechanism in ultrasonic deformation processes versus stress superposition (Graff, 2015).…”

Power Ultrasonic Additive Manufacturing: Process Parameters, Microstructure, and Mechanical Properties

“…In 1999-2000, White founded Solidica Inc. [3] in order to sell commercial UAM machines. UAM or UC is a solid-state technology for joining similar or dissimilar materials (usually metal foils) near room temperature by bonding them together layer by layer with ultrasonic vibrations under pressure to form 3D as-built parts [4]. e working principle of this technology is simple, and Figure 1 illustrates the UC process and setup components.…”