Mechanical Engineering Commons^™

Sustainability For Die Manufacturing: Comparative Study Of Wedm And Milling, Matthew S. Kalus

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Sustainability is more important in today's culture due to the increasing demand for a more eco-friendly society. Concentrations in minimizing and reducing environmental impacts, energy and natural resources have been forthcoming in industry. The tool, mold and die industries are the most well known industries that machine harder materials using mills and WEDM. The objective of this thesis was to compare the sustainability differences in both of these machines utilizing the accepted standards for evaluating the manufacturing process performance for sustainability. These standards include the evaluation of the process parameters, raw materials, power, tools and fluids which all contribute to …

Droplet Spray Behavior Of An Atomization-Based Cutting Fluid (Acf) System For Machining Of Titanium Alloys, Chandra Nath, Shiv G. Kapoor, Anil K. Srivastava, Jon Iverson

Manufacturing & Industrial Engineering Faculty Publications and Presentations

The aim of this research is to study droplet spray characteristics of an atomization-based cutting fluid (ACF) spray system including droplet entrainment angle and flow development regions with respect to three ACF spray parameters, viz., droplet and gas velocities, and spray distance. ACF spray experiments are performed by varying droplet and gas velocities. The flow development behavior is studied by modeling the droplets entrainment mechanism, and the density and distribution of the droplets across the jet flare. Machining experiments are also performed in order to understand the effect of the droplet spray behavior on the machining performances, viz., tool life/wear, …

Work In Progress: Outreach Assessment: Measuring Engagement, Lizabeth Schlemer, John Oliver, Katherine Chen, Sophia Rodriguez Mata, Eric Kim

Industrial and Manufacturing Engineering

The Learn By Doing Lab (LBDL) at Cal Poly, San Luis Obispo is an on-campus laboratory where 5th through 8th grade students are taught by undergraduates who may be planning a careers in teaching. The two populations - elementary students and undergraduates - are equally important in the process. Since 2008, the lab has seen over 4000 elementary and junior high students and over 100 undergrads have participated. In most outreach assessment the number of individuals participating is an important metric, but this last Spring we experimented with a more in depth measure of effectiveness. As in any learning experience …

Studying The Effect Of Laser Welding Parameters On The Quality Of Zek100 Magnesium Alloy Sheets In Lap Joint Configuration, Masoud Harooni, Fanrong Kong, Blair Carlson, Radovan Kovacevic

Mechanical Engineering Research

Magnesium, as the lightest structural metal, has been widely used in the automotive and aerospace industries. Porosity is the main issue in the welding of magnesium alloys and can be caused by surface coatings, hydrogen gas, pre-existing porosity, the collapse of an unstable keyhole and vaporization of alloying elements. In this study, the effect of the oxide layer on pore generation in the welding of AZ31B-H24 magnesium alloy is investigated. A fiber laser with a power of up to 4 kW is used to weld samples in a lap joint configuration. Two groups of samples are studied: as received (AR) …

Mitigation Of Pore Generation In Laser Welding Of Magnesium Alloy Az31b In Lap Joint Configuration, Masoud Harooni, Fanrong Kong, Blair Carlson, Radovan Kovacevic

Mechanical Engineering Research

Magnesium, as the lightest structural metal, has been widely used in the automotive and aerospace industries. Porosity is the main issue in the welding of magnesium alloys and can be caused by surface coatings, hydrogen gas, pre-existing porosity, the collapse of an unstable keyhole and vaporization of alloying elements. In this study, the effect of the oxide layer on pore generation in the welding of AZ31B-H24 magnesium alloy is investigated. A fiber laser with a power of up to 4 kW is used to weld samples in a lap joint configuration. Two groups of samples are studied: as received (AR) …

Comparison Of Compression Molding And Selective Laser Sintering Processes In The Development Of Composite Bipolar Plates For Proton Exchange Membrane Fuel Cells, Ehsan Taghipour, Ming-Chuan Leu, Nannan Guo

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Bipolar plates are key components of Proton Exchange Membrane (PEM) fuel cells. They carry current away from the cell and withstand the clamping force of the stack assembly. Therefore, PEM fuel cell bipolar plates must have high electrical conductivity and adequate mechanical strength, in addition to being light weight and low cost in terms of both applicable materials and production methods. In order to attain these goals, we have manufactured graphite-carbon- polymer composite plates using Compression Molding (CM), which is suitable for mass production, and Selective Laser Sintering (SLS), which is suitable for making prototypes. In this paper, the electrical …

Experimental Study Of Polymer Electrolyte Membrane Fuel Cells Using A Graphite Composite Bipolar Plate Fabricated By Selective Laser Sintering, Nannan Guo, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Selective Laser Sintering (SLS) can be used to fabricate graphite composite bipolar plates with complex flow fields for Polymer Electrolyte Membrane (PEM) fuel cells. The additive manufacturing process can significantly reduce the time and cost associated with the research and development of bipolar plates as compared to other fabrication methods such as compression molding. In this study, bipolar plates with three different designs, i.e., parallel in series, interdigitated, and bio-inspired, were fabricated using the SLS process. The performance of these SLS-fabricated bipolar plates was studied experimentally within a fuel cell assembly under various operating conditions. The effect of temperature, relative …

The Applications Of Additive Manufacturing Technologies In Cyber-Enabled Manufacturing Systems, Sriram Praneeth Isanaka, Frank W. Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The application of networked sensors and control in various areas, such as smart grids and infrastructures, has become a recent trend, called cyber-physical systems. The Cyber Enabled Manufacturing (CEM) environment is to apply these technologies in manufacturing systems to handle a significantly greater magnitude of manufacturing data. Additive manufacturing techniques print or place material layer by layer to form a part, thus have a great potential to help accelerate CEM process by printing or embedding sensors and actuators in the proper locations. This paper summarizes the roles of additive manufacturing technologies to help establish a CEM environment.

Modeling, Analysis And Simulation Of Paste Freezing In Freeze-Form Extrusion Fabrication, Mingyang Li, Robert G. Landers, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

During the freeze-form extrusion fabrication process for aqueous-based pastes, the sub-zero temperature environment aids the part in maintaining its shape by freezing the water present in the paste. The paste freezes very quickly when deposited on a substrate in a freezing environment. However, as the part’s height increases, the freezing time increases as the heat conduction rate to the substrate decreases. The freezing time can exceed the time required to extrude one layer of paste due to water’s high latent heat, thus leaving the extruded paste in its semi-liquid state and causing the part to deform or even collapse. Therefore, …

Interactions Of An Additive Manufacturing Program With Society, Frank W. Liou, Ming-Chuan Leu, Robert G. Landers

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Additive Manufacturing (AM) has shown considerable promise for the future but also proposes some challenges. Many AM barriers tend to be non-technical and instead are human-centric issues such as lack of education of practitioners in AM capabilities, cultural differences, vested interests, and potentially lack of imagination. It is highly desirable for all research and educational institutions to help address these issues. This paper summarizes the additive manufacturing research and education program at the Missouri University of Science and Technology (Missouri S&T) and its interactions with various constituents, including K-12 students, undergraduate and graduate students, distance students, and industry.

Freeze-Form Extrusion Fabrication Of Functionally Graded Material Composites Using Zirconium Carbide And Tungsten, Ang Li, Aaron S. Thornton, Bradley K. Deuser, Jeremy Lee Watts, Ming-Chuan Leu, Greg Hilmas, Robert G. Landers

Materials Science and Engineering Faculty Research & Creative Works

Ultra-high-temperature ceramics are being investigated for future use in aerospace applications due to their superior thermo-mechanical properties, as well as their oxidation resistance, at temperatures above 2000⁰C. However, their brittleness makes them susceptible to thermal shock failure. As graded composites, components fabricated as functionally-graded materials (FGMs) can combine the superior properties of ceramics with the toughness of an underlying refractory metal. This paper discusses the grading of two materials through the use of a Freeze-form Extrusion Fabrication (FEF) system to build FGM parts consisting of zirconium carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and W were developed …

Selective Laser Sintering; A Design Of Experiments, Philip David Hopkins, Victor Castillo Phd

STAR Program Research Presentations

Additive Manufacturing (AM), also commonly known as 3D Printing or Rapid Prototyping, is a method of manufacturing that provides for the ability to make intricate internal features and easily customizable parts. The concept is to break a Computer Aided Design (CAD) file into a series of thin layers that are sent to the machine and laid down one layer at a time. Just like any other form of processing, material properties can alter by undergoing this process. Manipulating various parameters of the AM process can allow for different properties to be achieved. For this reason, an in depth study will …

Study Of Grinding Burn Using Design Of Experiments Approach And Advanced Kaizen Methodology, Kiruthika Devi Sundarrajan

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

Grinding burn has been one of the re-occurring issues at a leading automotive manufacturer. Historically when grinding burn occurred, trial and error was used to delicately find a set up process settings that provided good-enough-to-get-by results, but not optimal. Some changes include changing the coolant manifold to improve the coolant flow and rate, changing the grinding wheel, changing the type of coolant. The experiments have proved to introduce some improvements, however the occurrence of grinding burns have not been reduced or quantified and the cause of the grinding burn has not been identified or quantified. Grinding is a complex phenomenon …

Integrating Courses Through Project Based Learning, Lizabeth Schlemer, Sema E. Alptekin, Karen R. Bangs

Industrial and Manufacturing Engineering

Integrating three courses (one sophomore level, two senior level) through Project Based Learning (PBL) within the Industrial Engineering curriculum at the California Polytechnic State University, San Luis Obispo is presented. Three courses (IME 443 Facilities Planning and Design - senior level; IME 420 Simulation - senior level; and IME 223 Process Improvement Fundamentals - sophomore level) were linked by various mechanisms: Common industry projects, common students in two of the three courses; senior students having access to sophomores in their teams to carry out time consuming tasks such as time studies, and sophomores having access to seniors as team members, …

Improving Manufacturing Processes Through Energy Monitoring, Andrew Grzelak

Purdue Polytechnic Masters Theses

Energy efficiency and sustainability are very popular topics in the current field of manufacturing. With the increase in use of automation technology as well as the recent growth in the area of energy management, there is much focus on the overall improvement of manufacturing processes. For this research a project was completed to create a system that could improve both process efficiency as well as decrease energy consumption. By taking a look at the machine level energy consumption of an automated piece of manufacturing equipment, by eliminating waste in process, both energy efficiency and operational efficiency can be improved.

Using …

Acoustic Emission Detection Of Metals And Alloys During Machining Operations, Jameson K. Nelson

Purdue Polytechnic Masters Theses

Nelson, Jameson K. M.S., Purdue University, May 2012. Acoustic Emission Detection of Metals and Alloys During Machining Operations. Major Professor: Rodney G. Handy.

Practical correlation between material deformation attributes and theoretical concepts of machining has proven difficult to attain. The purpose of this study was to further explore trends and relationships using acoustic emission detection of materials undergoing single-point lathe turning machine processes. The majority of machining experiments that incorporate acoustic emissions focuses on tool degradation for the purposes of optimizing consumables required to manufacture mechanical devices. Experiments were implemented varying recording location, mechanical barrier condition, and machine parameters. The …

Effect Of Gold Content On The Microstructural Evolution Of Sac305 Solder Joints Under Isothermal Aging, Mike Powers, Jianbiao Pan, Julie Silk, Patrick Hyland

Industrial and Manufacturing Engineering

Au over Ni on Cu is a widely used printed circuit board (PCB) surface finish, under bump metallization (UBM), and component lead metallization. It is generally accepted that less than 3 wt.% Au in Sn-Pb solder joints inhibits formation of detrimental intermetallic compounds (IMC). However, the critical limit for Au content in Pb-free solder joints is not well established. Three surface-mount package platforms, one with a matte Sn surface finish and the others with Ni/Au finish, were soldered to Ni/Au-finished PCB using Sn-3.0Ag- 0.5Cu (SAC305) solder, in a realistic manufacturing setting. The assembled boards were divided into three groups: one …

The Morphology Evolution And Voiding Of Solder Joints On Qfn Central Pads With A Ni/Au Finish, Julie Silk, Jianbiao Pan, Mike Powers

Industrial and Manufacturing Engineering

In this paper, we report on a comprehensive study regarding the morphology evolution and voiding of SnAgCu solder joints on the central pad of two different packages – QFN and an Agilent package called TOPS – on PCBs with a Ni/Au surface finish. Samples were isothermally aged at the equivalent of 0, 2, 7 and 14 years service life. Representative solder joints were cross-sectioned and analyzed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) in order to investigate the evolution of the solder joint morphology as a function of Au content and isothermal aging. IMC thickness was …

Simulations Of Non-Contact Creep In Regimes Of Mixed Dominance, Maija Benitz

Masters Theses 1911 - February 2014

Improvement of high temperature applications relies on the further development of ultra-high temperature materials (UHTMs). Higher performance and efficiency is driving the need for improvements in energy conversion and propulsion systems. Rocket nozzles, gas turbine engines and hypersonic aircraft depend on a better understanding of a material's performance at high temperatures. More specifically, the characterization of creep properties of high temperature materials is required. Conventional creep testing methods are limited to about 1700 degrees Celsius. Non-contact methods have been developed, which rotate spherical samples up to 33,000 rotations per second. A load is supplied by centripetal acceleration causing deformation of …

Factors Impacting Technology Transfer: The Maquiladora Industry In Yucatan, Mexico, Ana Maria Canto, Carlos Blanco, Pilar Pazos

Engineering Management & Systems Engineering Faculty Publications

Technology transfer and knowledge transfer are the building blocks for innovation, efficiency and increased competitiveness. The topic of technology transfer in the context of multinational companies has been the focus of technology management researchers for well over two decades. Developing countries housing twin plans have been exposed to technology transfer from very diverse countries with different approaches to the technology transfer process and different levels of success. This cultural and national diversity adds an additional level of complexity to the technology transfer domain that has been largely unexplored. This paper will explore critical factors that had an impact in successful …