Mechanical Engineering Commons^™

Laser Assisted Direct Writing Of Liquid Metal For Microprinting Applications, Olga Vargas Cruz

Theses and Dissertations

This paper presents a research study for potential printing of a Liquid Metal (LM) Eutectic Gallium Indium alloy (EGaIn) through the applications of the innovative additive manufacturing technology LIFT (Laser Induced Forward Transfer). LIFT is a precise printing technology that allows to create small, detailed printing. The liquid metal in study, EGaIn, has demonstrated great potential for microelectronics applications due to its minimum toxicity and high conductivity. Throughout this research different printing parameters are studied to comprehend the behavior of EGaIn printing with LIFT technique, these include laser energy, laser pulse, receiver material substrate, donor layer thickness, and …

Additive Manufacturing Of Stretchable Strain Sensors: Fabrication, Optimization And Application, John Nady Shihat Bastawrous

Theses and Dissertations

In this project, a novel strain sensor design is fabricated employing different additive manufacturing techniques. The spring sensor's primary material is PLA-Like resin with a nanocomposite encapsulation layer as the functional material. The main principle of Straining the sensors results in a change in resistivity as the distances among the conductive carbon particles change according to the strain applied.

Sensor fabrication consists of two parts: spring manufacturing and development of nanocomposite encapsulation The nanocomposite matrix is developed through the dispersion of Graphene and Carbon nanotubes in Thermoplastic Polyurethane through sonication and magnetic hotplate stirring. While the spring itself is manufactured …

Additive Manufacturing Of Cork, A Cold Spray Technology, Kimberly Kay Dickey

Theses and Dissertations

Cold Spray Additive Manufacturing is a technology capable of mass manufacturing components with complicated geometry and coating substrates in hard-to-reach areas. In addition, cold spray also has the ability of conducting a green manufacturing process, with zero waste of renewable feed material, and zero gas and chemical emission. This paper investigates solely cold spray as an additive manufacturing technology with cork as the natural material. CFD results were used to predict the physical behavior of air and the cork particles. After unsuccessful coatings, final results showed that when moisture is added, cork is successfully cold sprayed, and agglomeration is experienced. …

Prediction Of Residual Stress And Distortion In Laser Powder Bed Fusion Additive Manufacturing, Bhanuprakash Sairam Kosaraju

Theses and Dissertations

Additive Manufacturing (AM) has its proven advantages to unlock the design space and manufacturing capabilities for complex geometries with lightweights. Distortion is one of the most common defects that occur in Laser Powder Bed Fusion Additive Manufacturing (LPBFAM), which is caused by the significant residual stress during the printing process. This can lead to numerous process iterations to achieve the requisite form and fit tolerances.

In this study, Finite Element (FE) model that utilizes the element birth approach was developed to predict the residual stress and distortion in the LPBFAM process. The methodology leverages a simplified approach where the detailed …

Fracture Toughness And Fatigue Crack Growth Rate Characterization Of Inconel 718 Formed By Laser Powder Bed Fusion, Charles C. Hohnbaum

Theses and Dissertations

Continuing improvement in the field of AM of metals provides the opportunity for direct fabrication of aerospace parts. AM was once used in large part for rapid prototyping but improvements in technology and increases in the knowledge base of AM materials has provided the opportunity for manufacture of AM parts for operational use. The ability to create low numbers of unique parts without having to invest in expensive tooling provides great economic incentive to utilize this technique. IN718 is the most common high temperature alloy used in the aerospace industry and lends itself readily to formation by LPBF. The superior …

Process Parameter Development Of Additively Manufactured Af9628 Weapons Steel, Erin M. Hager

Theses and Dissertations

The manufacture of components in Additive Manufacturing processes is limited by the range of materials available. Qualification of materials for Additive Manufacturing is time intensive, and is often specific to a single type of machine. In this study, an approach to selecting power, speed, and hatch spacing values for a newly powderized material, AF9628 weapons steel, is described that results in highly dense (>99.9%) parts on an MLab 200R Cusing. Initial power and speed values used in a weld track study were selected based on a survey of parameters used on similar materials, with a focus on the energy …