Using Literature Reviews as a Learning Tool for Solid Freeform Fabrication

Over the past six years, students involved in the “Non-Traditional & Additive Manufacturing” course at Utah State University have been assigned an in-depth literature review as one their course projects. This literature review, done in groups of 2 or 3 students, involves becoming an expert on a topic of interest to the students and then presenting this material to the class as an indepth, oral presentation in addition to writing a journal-like review article on the topic. This project has proved to be a consistently effective method for enhancing learning of SFF technologies and their applications, and has been consistently noted by students in their course evaluations as a highly effective teaching tool. The methodology used for assigning and assessing these projects will be explored, in addition to a discussion of the benefits of this project toward meeting ABET criteria for accreditation of engineering programs.Mechanical Engineerin

Transport improvement, commuting costs, and residential location

A theoretical framework for evaluating the effects of introducing new transportation on residential travel patterns is presented. Data are based on changes in residential location of urban commuters that alter the mode and length of work trips as well as economic factors

Development of a Co-Cr-Mo to Tantalum Transition using LENS for Orthopedic Applications

Biomedical implant material research using additive manufacturing is a popular field of study. Many potential material combinations exist which, if implemented properly, could have a significantly positive effect on implant life and functionality. One material combination of interest is attaching porous Ta bone ingrowth material to a CoCrMo corrosion and wear resistant bearing surface. An investigation of the ability of the LENS process to join Ta to CoCrMo was undertaken. Direct joining of CoCrMo to Ta was known to be problematic, and thus transitional layers of other biomedically-compatible materials were investigated. It was determined that a transitional layer of zirconium appeared to be the best transitional material for this application due to its excellent biocompatibility, followed by stainless steel, with a lesser biocompatibility but better adhesive properties.Mechanical Engineerin

Deposition of Ti/TiC Composite Coatings on Implant Structures Using Laser Engineered Net Shaping

A new method of depositing hard and wear resistant composite coatings on metal-onmetal bearing surfaces of titanium implant structures is proposed and demonstrated. The method consists of depositing a Ti/TiC composite coating (~ 2.5 mm thick) on titanium implant bearing surfaces using Laser Engineered Net Shaping (LENS®). Defect-free composite coatings were successfully produced at various amounts of the reinforcing TiC phase with excellent interfacial characteristics using a mixture of commercially pure Ti and TiC powders. The coatings consisted of a mixture of coarser unmelted/partially melted (UMC) TiC particles and finer, discreet resolidified (RSC) TiC particles uniformly distributed in the titanium matrix. The amounts of UMC and RSC were found to increase with increasing TiC content of the original powder mixture. The coatings exhibited a high level of hardness, which increased with increasing TiC content of the original powder mixture. Fractographic studies indicated that the coatings, even at 60 vol.% TiC, do not fail in a brittle manner. Various aspects of LENS® deposition of Ti/TiC composite coatings are addressed and a preliminary understanding of structure-property-fracture correlations is presented. The current work shows that the proposed approach to deposit composite coatings using laser-based metal deposition processes is highly-effective, which can be readily utilized on a commercial basis for manufacture of high-performance implants.Mechanical Engineerin

Process Parameters Optimization for Ultrasonically Consolidated Fiber-Reinforced Metal Matrix Composites

As an emerging rapid prototyping technology, Ultrasonic Consolidation (UC) has been used to successfully fabricate metal matrix composites (MMC). The intent of this study is to identify the optimum combination of processing parameters, including oscillation amplitude, welding speed, normal force, operating temperature and fiber orientation, for manufacture of long fiber-reinforced MMCs. The experiments were designed using the Taguchi method, and an L25 orthogonal array was utilized to determine the influences of each parameter. SiC fibers of 0.1mm diameter were successfully embedded into an Al 3003 metal matrix. Two methods were employed to characterize the bonding between the fiber and matrix material: optical/electron microscopy and push-out tests monitored by an acoustic emission (AE) sensor. SEM images and data from push-out tests were analyzed and optimum combinations of parameters were achieved.Mechanical Engineerin

Multi-Material Ultrasonic Consolidation

Ultrasonic consolidation (UC) is a recently developed direct metal solid freeform fabrication process. While the process has been well-demonstrated for part fabrication in Al alloy 3003 H18, including with intricate cooling channels, some of the potential strengths of the process have not been fully exploited. One of them is its flexibility with build materials and the other is its suitability for fabrication of multi-material and functionally graded material parts with enhanced functional or mechanical properties. Capitalizing on these capabilities is critical for broadening the application range and commercial utilization of the process. In the current work, UC was used to investigate ultrasonic bonding of a broad range of engineering materials, which included stainless steels, Ni-base alloys, brass, Al alloys, and Al alloy composites. UC multimaterial part fabrication was examined using Al alloy 3003 as the bulk part material and the above mentioned materials as performance enhancement materials. Studies were focused on microstructural aspects to evaluate interface characteristics between dissimilar material layers. The results showed that most of these materials can be successfully bonded to Al alloy 3003 and vice versa using the ultrasonic consolidation process. Bond formation and interface characteristics between various material combinations are discussed based on oxide layer characteristics, material properties, and others.Mechanical Engineerin

Home Schooling: A Resource Guide for Parents and Teachers

Home schooling was researched for the purpose of determining how many students are home schooled, the rules and regulations regarding home schooling, and the effectiveness of home schooling. A resource guide has been developed for home schooling parents and teachers dealing with home schoolers. Many of the resources are geographically specific to the Yakima Valley, but most can be used or adapted for a variety of age and maturity levels. The guide is divided into three topics: Public Resources, Private Resources, and Community Resources

Structurally Embedded Electrical Systems Using Ultrasonic Consolidation (UC)

Current research has demonstrated the use of Ultrasonic Consolidation (UC) to embed several USB-based sensors into aluminum, and is working toward embedding suites of sensors, heaters and other devices, connected via USB hubs, which can be monitored and controlled using an embedded USB capable processor. Additionally, the research has shown that electronics can be embedded at room temperature, but with some inter-layer delamination between the ultrasonically bonded aluminum layers. Embedding sensors and electronics at 300o F to overcome the delamination issues resulted in optimal bonding, and the sensors used thus far have functioned normally. Future investigation will explore other UC parameter combinations to ascertain the quality of embedding at lower temperatures.Mechanical Engineerin