Archives—September 2011

Ultrafine Grained Ti-6Al-4V for Aerospace Applications

Friday, September 30, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Dr. Judson S. Marte
General Electric Global Research Center Niskayuna, NY

Abstract

Improving the performance and reducing the cost of titanium components is important for aerospace applications, such as gas turbine engines. This presentation will provide an overview of an ongoing collaborative program between ATI Allvac and GE evaluating the production, characterization, and application of ultrafine-grained titanium. Multi-axis forging (MAF) has been used to produce bulk samples with submicron alpha grain size. Extensive characterization of the microstructure shows that, after MAF, the beta phase tends to pin alpha, enhancing thermal stability. Deformation properties have been evaluated and used to make finite element models of near-net shape forging processes. Laboratory-scale near-net shape forgings have been produced to demonstrate feasibility and provide material for microstructural and mechanical evaluation. Tensile and fatigue performance of the sub-scale forgings will be presented, as will a brief discussion of the challenges associated with developing a full-scale forging process.

Biography

Jud is currently the Manager of the Metals Processing and Testing Laboratory at GE Global Research in Niskayuna, NY. He is also a project leader and metallurgist who specializes in the thermomechanical processing of structural metals, low temperature superconductors, and magnetic materials. Prior to joining GE in 1999, he earned his PhD in Materials Science and Engineering at Virginia Tech studying the synthesis and processing of titanium- and titanium aluminide- matrix composites.


Michigan Tech Dedicates New Solar Energy Research Facility

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“This is plug and play,” said Joshua Pearce, an associate professor of materials science and engineering and electrical and computer engineering. Microinverters help drive down the price of solar energy and make it more and more attractive to a mass market. As a result, “solar can now play ball in places where electricity is costly, like Hawaii,” he said.



An Overview of Metallurgical Failure Analysis

Friday, September 23, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Joel F. Flumerfelt, PhD
Metallurgist Aspen Research Corporation, St. Paul, MN

Abstract

Materials have been used throughout history for various applications, for example, tools, weapons, buildings, vehicles and ornamentation. Invariably, components used within these products sometimes fail during service before their expected end of life. The past three decades have seen extreme failures that caused human fatalities, for example, the Space Shuttle Challenger explosion shortly after lift-off in 1986, the Space Shuttle Columbia explosion upon re- entry in 2003, and collapse of the Interstate 35W Mississippi River Bridge in Minneapolis, Minnesota, in 2007. When failure happens, there is usually a mandate to identify factors that contributed to the failure to make plans for avoiding failure in the future, i.e. design and build a better mouse trap. A failure analysis investigation satisfies the demand such that the work effort identifies: the failure mode; the immediate primary cause(s) for the failure; the root cause(s) for the failure associated with intentional and unintentional human errors. This presentation will illustrate the principles of the failure analysis process using a recent failure investigation related to a socket head cap screw that failed inside a shaker table.

Biography

Joel is a metallurgist who began his career at Aspen Research Corporation in 2000. As an analyst, he participates in various short term projects that address client inquiries related to failure analysis, foreign residue and deposit identification, microscopic examinations, mechanical testing, customized test method development, material selection and design, material and product quality control measures, and product process development and improvement. As a project manager, he interacts with Aspen’s clients to understand and respond to questions about material and process issues associated with their products, providing customized quotes that define a project’s objective, scope of work, cost, and timeline. He also oversees the operation and maintenance of the metallurgical lab, optical microscopes and SEM-EDS instrumentation.
Prior to joining Aspen Research Corporation, he spent 18 months at Engel Metallurgical, Ltd. (St. Cloud, MN) working on projects related to metallurgical failure analysis and material selection and design.
Joel holds a Bachelor of Science and Master of Science degree in Metallurgical Engineering from Michigan Technological University, and a Doctorate degree in Metallurgical Engineering from Iowa State University. He is a current member of ASM International and SMTA. A hobby of his is playing alto sax with a 17 person swing band, named “Red Rock Swing Band”, which performs at different locales around the Twin City metropolitan area for private and public gigs.


Michigan Tech to Dedicate New Solar Energy Research Center

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The Michigan Tech Solar Photovoltaic Research Facility includes an array of solar panels and an advanced energy-monitoring system at KRC’s Engineering Design Building.

KRC is known for its research relating to snow and ice, so it might not seem like an ideal location for studying solar-energy systems. But the region’s demanding weather provides a big advantage, says energy researcher Joshua Pearce. “This will allow us to evaluate solar-energy systems in real-world conditions,” said Pearce, an associate professor who holds a dual appointment in the Departments of Materials Science and Engineering and Electrical and Computer Engineering.

Other Michigan Tech faculty members using the Solar Photovoltaic Research Facility in materials science and engineering are Stephen Hackney, Miguel Levy, Yun Hu and Peter Moran.


In the News

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Michigan Tech was mentioned in an article, “Recycling Mining Tailings on Lake Superior,” an initiative in which several University faculty and researchers have been involved. The story detailed efforts to use Upper Michigan’s stamp sands for roofing shingles. Michigan Tech scientists who have contributed to the initiative include Associate Professor Ralph Hodek (CEE), Professor Jim Hwang (MSE/IMP) and Research Assistant Professor Bowen Li (MSE/IMP). As well, Jim Baker, executive director of Innovation and Industry Engagement, has been involved. The prospect of using stamp sand for a roofing application is headed by alumnus and entrepreneur Domenic Popko ’93 ’99, of Traverse Bay. Popko worked at IMP for five years. The story appeared in Environmental Leader, a daily trade publication about energy, environment, and sustainability.



Ab Initio Investigation and Thermodynamic Modeling of Shape Memory Alloys

Friday, September 9, 2011 3:00 pm – 4:00 pm
Room 610, M&M Building

Arpita Chari, Navdeep Singh Department of Mechanical Engineering, Texas A&M University

Abstract

Shape Memory Alloys are an interesting class of active materials that undergo reversible shape changes through martensitic transformations that can be triggered by temperature, stress and/or magnetic fields (in the case of ferromagnetic SMAs). Among recently investigated SMAs, Co2NiGa and Co2NiAl alloys have been receiving considerable interest due to their shape memory (SM) properties. While there have been many investigations on the mechanical and magnetic behavior of these materials, very little is known about the fundamental microscopic basis for the observed macroscopic behavior.
In the first part of the talk, we discuss the stability of Co2NiGa and Co2NiAl-based structures. The transformation of the cubic austenite to the tetragonal martensite structure is investigated through Bain distortion paths as well as lattice dynamical calculations. Analysis of the features of the electronic structure are then mapped to the observed metastability of the cubic phases with respect to tetragonal deformations and comparisons are made with the much more studied Ni2MnGa-based SMAs. We also investigate the magnetic behavior of these alloys by using Monte Carlo simulations in combination with ab initio methods.
In the second part of the talk we will focus on the use of the first-principles calculations in combination with experimental information to develop accurate thermodynamic models —based on the CALPHAD approach—for the Co-Ni-Ga ternary system. These thermodynamic models are then used to predict phase constitution as a function of alloy composition and temperature. Reliable thermodynamic models can be used in the computer-aided design of novel shape memory alloys based on this ternary system.

Biography

Dr. Arroyave got his B. S. in Mechanical and Electrical Engineering at ITESM (Monterrey, Mexico). Afterwards, he enrolled at the Massachusetts Institute of Tecnoloogy, where he got his M. S. (2000) and Ph.D. (2004) in Materials Science and Engineering under the supervision of Prof. Thomas W. Eagar. After two and a half years as a Postdoctoral Scholar in Prof. Zi-Kui Liu’s group at Penn State he joined the faculty of Mechanical Engineering and Materials Science at Texas A&M University in 2006. Dr. Arroyave’s expertise is in computational thermodynamics and kinetics of materials (using the CALPHAD method), phase-field methods and use of electronic structure methods to predict the structural/functional properties of materials at the atomic scale. Dr. Arroyave’s group is also working with experimental colleagues to develop Integrated Computational Materials Engineering (ICME) approaches to optimize complex multi-phase, multi-component structural alloys.


Presidential Council of Alumnae on Campus

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The Presidential Council of Alumnae (PCA) will hold its annual meeting and induction of new members Thursday-Saturday, Sept. 15-17, on campus. This year marks the 16th anniversary of the organization, which has 159 members. The PCA advises the president on campus climate issues and works to enhance the University’s environment for all students.

The PCA will recognize 23 outstanding students as Women of Promise, including Amberlee Lifer (MSE).