Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 4 of 4

Full-Text Articles in Engineering

Adhesion Testing Of Printed Inks While Varying The Surface Treatment Of Polymer Substrates, Clayton Neff, Edwin Elston, Amanda Schrand, Nathan B. Crane Sep 2019

Adhesion Testing Of Printed Inks While Varying The Surface Treatment Of Polymer Substrates, Clayton Neff, Edwin Elston, Amanda Schrand, Nathan B. Crane

Faculty Publications

Additive manufacturing with conductive materials enables new approaches to printed electronics that are unachievable by standard electronics manufacturing processes. In particular, electronics can be embedded directly into structural components in nearly arbitrary 3D space. While these methods incorporate many of the same materials, the new processing methods require standard test methods to compare materials, processing conditions, and determine design limits. This work demonstrates a test method to quantitatively measure the adhesion failure of printed inks deposited on a substrate without changing the ink printing conditions. The proposed method is an adaption of single lap shear testing in which the lap …


Mechanical And Temperature Resilience Of Multi-Material Systems For Printed Electronics Packaging, Clayton Neff, Justin Nussbaum, Chris Gardiner, Nathan B. Crane, James L. Zunino, Mike Newton Sep 2019

Mechanical And Temperature Resilience Of Multi-Material Systems For Printed Electronics Packaging, Clayton Neff, Justin Nussbaum, Chris Gardiner, Nathan B. Crane, James L. Zunino, Mike Newton

Faculty Publications

In this work, two AM technologies were utilized to compare the effectiveness of fabricating a simple electronic device with a conductive trace and hollow cylinder representative of ‘printed packaging’ that would survive harsh environmental conditions. The printed packaging cylinder delineates printed potting for electronics packaging. An nScrypt direct write (DW) system was the primary manufacturing system but a developing technology—coined large area projection sintering (LAPS)—manufactured a subset of samples for comparison. The tests follow Military Standard (MIL STD) 883K and include resiliency evaluation for die shear strength, temperature cycling, thermal shock, and high G loading by mechanical shock. Results indicate …


Modeling Thermal And Mechanical Cancellation Of Residual Stress From Hybrid Additive Manufacturing By Laser Peening, Guru Madireddy, Chao Li, Jingfu Liu, Michael P. Sealy Jul 2019

Modeling Thermal And Mechanical Cancellation Of Residual Stress From Hybrid Additive Manufacturing By Laser Peening, Guru Madireddy, Chao Li, Jingfu Liu, Michael P. Sealy

Department of Mechanical and Materials Engineering: Faculty Publications

Additive manufacturing (AM) of metals often results in parts with unfavorable mechanical properties. Laser peening (LP) is a high strain rate mechanical surface treatment that hammers a workpiece and induces favorable mechanical properties. Peening strain hardens a surface and imparts compressive residual stresses improving the mechanical properties of a material. This work investigates the role of LP on layer-by-layer processing of 3D printed metals using finite element analysis. The objective is to understand temporal and spatial residual stress development after thermal and mechanical cancellation caused by cyclically coupling printing and peening. Results indicate layer peening frequency is a critical process …


Glocal Integrity In 420 Stainless Steel By Asynchronous Laser Processing, Michael P. Sealy, Haitham Hadidi, Cody Kanger, X. L. Yan, Bai Cui, J. A. Mcgeough Jan 2019

Glocal Integrity In 420 Stainless Steel By Asynchronous Laser Processing, Michael P. Sealy, Haitham Hadidi, Cody Kanger, X. L. Yan, Bai Cui, J. A. Mcgeough

Department of Mechanical and Materials Engineering: Faculty Publications

Cold working individual layers during additive manufacturing (AM) by mechanical surface treatments, such as peening, effectively “prints” an aggregate surface integrity that is referred to as a glocal (i.e., local with global implications) integrity. Printing a complex, pre-designed glocal integrity throughout the build volume is a feasible approach to improve functional performance while mitigating distortion. However, coupling peening with AM introduces new manufacturing challenges, namely thermal cancellation, whereby heat relaxes favorable residual stresses and work hardening when printing on a peened layer. Thus, this work investigates glocal integrity formation from cyclically coupling LENS® with laser peening on 420 stainless steel.