Materials Science and Engineering Commons^™

Migration Models - Comparison Of Pvc, Pet And Pla Diffusivity, Combined With A Production Cost Model For Westridge Laboratories, Shelley Cooke, Sarina Surrette

Materials Engineering

This project has two parts: [1] a migration and diffusivity model for candidate plastics used in containers, and [2] a product cost model for Westridge Laboratories (Santa Ana, CA).

Diffusion modeling is a useful tool to predict migration of polymer constituents into exposed liquids.  Polyvinyl chloride (PVC), polyethylene terephthalate (PET) and polylactic acid (PLA) were studied to estimate production costs, and component migration into water-based liquids from plastic containers.  Bis (2-ethylhexyl) phthalate (DEHP), antimony trioxide, and stannous octoate, are components of concern in the three candidate polymers, respectively.  Normal detection limits for these constituents are about 1 - 10 ppb, …

The Effects Of Carbon, Boron And Vanadium On The Microstructural Evolution And Hardness Of Steel-Based Hardfacing Alloys, Kyle Rafa

Materials Engineering

Current hardfacing alloys provide insufficient wear resistance due to either cracking or significant material wear. To increase wear resistance of steel-based hardfacing alloys, the effects of composition on microstructure and hardness were investigated in a progression of alloys. Initially, seven new alloys were prepared varying the carbon-boron ratio with the total constant at 3 wt%. Small arc-melt cast circular ingots were produced roughly 1 x 0.5 inches. Metallography provided insufficient phase magnification, thus a SEM equipped with EDS was used, allowing for microstructure and phase composition analysis. Four distinct carbide phases were found and image analysis software allowed for carbide …

Characterization Of Aluminum-Boron Carbide Particulate Metal Matrix Composites, Eric Blank

Materials Engineering

The analysis of die-cast 380 aluminum-boron carbide particulate metal matrix composites (MMC) was performed in order to see if the samples had the required tensile strength of 300 MPa. 10wt% B4C die-cast samples were produced and tested. Half were heat treated to the T6 condition and the others were left as cast. Using ASTM standard B 557M it was found that the average tensile strength for the as-cast samples was 130 MPa and the heat treated samples had a tensile strength of 93 MPa. These values were both lower than expected. The heat treated samples were not expected to have …

Effects Of A Solution Anneal Quench Delay On The Heat Treatment Response Of Aluminum 2219-T6, Daniel James Filomeo

Materials Engineering

The ageing response for aluminum 2219-T6 was investigated to determine the effects a quench delay (QD) could have on tensile properties. Before testing commenced, furnace surveys were conducted to ensure they could meet the required temperature stability of + 10˚F (+6˚C). MIL-H-6088 specified a maximum quench delay of 15 seconds for parts thicker than 2.29 mm (0.090 in). An investigation was conducted on how different quench delay times changed the ageing response of T6 heat treated for Al 2219. Heat treatments were performed according to the ASM Handbook. Preliminary tests were performed on 1-1.5 in. cube blocks of Al 2219 …

Validation Of A Secondary Fabric Supplier And Characterization Of Alternate Cores For Use In The Aptera 2e Sandwich Core Composite, Bryan Rogers

Materials Engineering

Polymer matrix composites’ high strength to weight ratio has made them an ideal material choice for use in lightweight transportation vehicles. Aptera Motors, a company based out of Oceanside, CA, is currently developing a next-generation high efficiency passenger vehicle called the Aptera 2e. The 2e’s body is composed of a sandwich core composite containing laminates of E-glass fibers embedded within an epoxy matrix sandwiched between a polyester hexagonal core. This project looked to validate a secondary fabric supplier for use in Aptera’s composite and characterize the core shear properties of two alternate core materials for future iterations of Aptera’s vehicle. …

Peak Stir Zone Temperatures During Friction Stir Processing, Sprinivasan Swaminathan, Keiichiro Oh-Ishi, Alexander P. Zhilyaev, Christian B. Fuller, Blair London, Murray W. Mahoney, Terry R. Mcnelly

Materials Engineering

The stir zone (SZ) temperature cycle was measured during the friction stir processing (FSP) of NiAl bronze plates. The FSP was conducted using a tool design with a smooth concave shoulder and a 12.7-mm step-spiral pin. Temperature sensing was accomplished using sheathed thermocouples embedded in the tool path within the plates, while simultaneous optical pyrometry measurements of surface temperatures were also obtained. Peak SZ temperatures were 990 ⁰Cto 1015 ⁰C (0.90 to 0.97 TMelt) and were not affected by preheating to 400⁰C, although the dwell time above 900 ⁰C was increased by the preheating. Thermocouple data suggested little variation in …

Application Of Self-Determination And Self-Regulation Theories To Course Design: Planting The Seeds For Adaptive Expertise, Linda Vanasupa, Jonathan Stolk, Trevor Harding

Materials Engineering

The paper is grounded in the premise that learning occurs within a dynamic system of social and ecological interactions in the learning environment. Our intent is to open the conversation about hose ac, as engineering educators, design effective learning experiences for this dynamic system, particularly in light of the deeply ethical, adaptive expertise required of today's graduates. Drawing from two well-researched theories of psychological development (self-determination and self-regulation), we assert that fostering the engagement and positive growth required for adaptive expertise necessitates a holistic educational approach. This approach requires us to consider both the psychological needs of the learner, and …

The Systemic Correlation Between Mental Models And Sustainable Design: Implications For Engineering Educators, Linda Vanasupa, Roger Burton, Jonathan Stolk, Julie B. Zimmerman, Larry J. Leifer, Paul T. Anastas

Materials Engineering

Many studies have illuminated our understanding of the kinds of competencies and behaviors exhibited by effective designers. Against the backdrop of global challenges made more urgent by unintentional negative impacts of engineered products and systems, however, we are left to deduce that our ways of educating engineering designers is fundamentally flawed. We assert that one can trace the cause of our collective, unintended negative consequences to the mental models of reality that we consciously or unconsciously carry. In this paper, we present the case for developing awareness and facility with mental models. We also suggest an alternate mental model as …

Workshop - Feminist Engineering Education: Building A Community Of Practice, Alice L. Pawley, Donna Riley, Susan M. Lord, Trevor S. Harding

Materials Engineering

As a result of a series of papers and special sessions held at FIE between 2004 and 2008, a community of CSET educators interested in exploring feminist pedagogies has formed at FIE. Past participants in these sessions have expressed a desire to learn more about what makes a set of pedagogies "feminist." At the same time, there has been an increase in the number of research papers at FIE that draw on feminist research methods or topics. This workshop is designed to meet the needs of members of the FIE community who have some experience with feminist pedagogies or research …

Work In Progress - A Mixed-Methods Approach To Developing An Instrument Measuring Engineering Students' Positive Ethical Behavior, Mathew A. Holsapple, Cynthia J. Finelli, Donald D. Carpenter, Trevor S. Harding, Janel A. Sutkus

Materials Engineering

Ethics education and the drive to produce ethical professional engineers is an important focus of one body of research on engineering education. This research often defines the positive outcome of ethics education as students and professional engineers choosing not to engage in unethical behavior. This paper discusses a portion of a larger research project and details efforts to identify and validate a definition of ethical behavior that includes the decision to engage in a positive behavior, defined as a service to a larger community. Through a series of interviews and focus groups with engineering administrators, faculty, and students, the authors …

The Effects Of Thermal Annealing On The Obliquely Deposited Ag–Ge–S Thin Films, F. Wang, W. P. Dunn, M. Jain, C. De Leo, N. Vicker, Richard N. Savage, Xiaomin Jin, S. Mamedov, P. Boolchand

Materials Engineering

Obliquely deposited thin films of ternary Ag–Ge–S glasses are characterized in this work. Thin films are fabricated in a vacuum thermal evaporator at different evaporation angles and examined by Raman spectroscopy. The Raman mode frequency of GeS₄ corner-sharing (CS) structure of the as-deposited films display a red-shift as a function of Ag content due to reduced global connectivity, and therefore decreased network stress. Film thickness of normally deposited thin films is significantly less when compared against obliquely deposited ones. Sulfur-ring (S₈) modes are observed in thin films but not in corresponding bulk material. Thermal annealing of thin …

Utilizing Quantum Dots To Enhance Solar Spectrum Conversion Efficiencies For Photovoltaics, Richard N. Savage, Hans Mayer, Matthew Lewis, Dan M. Marrujo

Materials Engineering

Silicon-based photovoltaics typically convert less than 30% of the solar spectrum into usable electric power. This study explores the utilization of CdSe based quantum dots as spectral converters that absorb the under utilized UV portion of the solar spectrum and fluoresce at wavelengths near the band-gap of silicon-based solar cells. A flexible 1 mm thick thin-film structure that contains an array of microfluidic channels is designed and fabricated in polydimethylsiloxane (PDMS) using soft-lithographic techniques. The channels are approximately 85 microns wide by 37 microns tall and are filled with a solution containing the quantum dots. The thin-film structure can easily …

Work In Progress - Attaining And Measuring Global Competency For Engineering Graduates, James Widmann, Linda Vanasupa

Materials Engineering

Downey et al. laid out a clear path of learning criteria and outcomes for global competence in their 2006 Journal of Engineering Education publication. We build on their work by integrating other disciplinary perspectives to expand upon the questions: "How can global competency be learned?", and "How can we assess it?" In this work-in-progress paper, we propose an expanded framework for global competence and identify the use of Fink's taxonomy of significant learning as a tool to consider how it can be achieved through careful design of classroom learning experiences. Drawing heavily from other models, our framework attempts to articulate …

Work In Progress - A Design Guide To Retain Female (And Male) Students In Engineering, Linda Vanasupa, Katherine C. Chen, Stacey Breitenbach, Karen R. Bangs

Materials Engineering

Despite a rich body of research on factors contributing to attrition of women during the college, women continue to be underrepresented in the graduating classes of most traditional engineering disciplines. We present our Four-Domain Development Diagram (4DDD) in an attempt to enable a systems approach to managing all the factors that contribute to retention. This diagram makes explicit the connections between the learners' response factors in the learning environment, including motivation, interest, and ultimately retention. Although we are only three years into our use of the diagrams' relationships, we have seen a lower overall net attrition rate (male and female) …

Work In Progress – Building The Survey Of Engineering Ethical Development (Seed) Instrument, Janel A. Sutkus, Donald D. Carpenter, Cynthia J. Finelli, Trevor S. Harding

Materials Engineering

When developing surveys, researchers can readily identify the concepts they intend to study, but how do they create individual survey items that will most accurately measure those concepts? Here we describe the first year of a four-year NSF project in which the E³ Team (Exploring Ethical Decision Making in Engineering) prepared to develop a national survey of the curricular and cocurricular activities, events, and experiences affecting the ethical development of engineering undergraduates. As this survey is likely to be the most comprehensive assessment of ethical development - both in content and scope - ever administered to engineering undergraduates, it …

The Psychology Of 'Ought', Trevor S. Harding

Materials Engineering

As educators, we would like to believe that we can influence the ethical growth of our students. If we are to do this, it seems worthwhile to first understand what ethical decision-making is and how it happens. For millennia, ethical decision-making has fallen within the domain of philosophy. However, recent evidence suggests that the average person does not consider ethical dilemmas in the abstract. Instead, ethical decision-making appears to be a complex dance between an individual’s rational calculus of the ethical dilemma and their emotional response to the context of the dilemma. I will present an argument that in the …

A Longitudinal Study Of The Ethical Development Of Engineering And Non-Engineering Students At A National Research University, Cynthia J. Finelli, Janel A. Sutkus, Donald D. Carpenter, Trevor S. Harding

Materials Engineering

No abstract provided.

The Four-Domain Development Diagram: A Tool For Designing Development-Centered Teaching, Linda Vanasupa, Trevor S. Harding, William L. Hughes

Materials Engineering

Research in education has brought to light the complexity of the learning process, demonstrating that students' development is influenced by a myriad of cultural and social factors, as well as the environment in which learning takes place. Engineering curricula, however, are primarily focused on teaching content knowledge, often resulting in a gap between what is taught and what is learned. We propose that shifting some of the focus onto the process of learning that occurs within the student and leveraging multiple known connections from educational psychology can result in more effective engineering education. Here we define “effective” engineering education as …

Converting Traditional Materials Labs To Project-Based Learning Experiences: Aiding Students' Development Of Higher-Order Cognitive Skills, Linda Vanasupa, Katherine C. Chen, Jonathan Stolk, Richard N. Savage, Trevor S. Harding, Blair London, William L. Hughes

Materials Engineering

Against a backdrop of compelling societal needs, graduates in science and engineering now must master their disciplines and demonstrate a sophisticated level of cognitive, affective and social development. This has lead a number of national and international commissions on science and engineering to urge educators to re-think the way in which STEM disciplines are taught. We have chosen to "repackage" a traditional undergraduate materials engineering curriculum in a form designed to promote the development of higher-order cognitive skills like self-directed learning and design. Classic metallurgy experiments have been converted to project-based learning experiences where students are put in the role …

Work-In-Progress - Self-Directed Learning And Motivation In A Project-Based Learning Environment, Trevor S. Harding, Linda Vanasupa, Richard N. Savage, Jonathan D. Stolk

Materials Engineering

Self-directed learning is a key competency in life-long learning, an outcome often cited for engineering education, and is dependent on students' motivation, meta-cognition, and self-regulation with regards to a learning task. Few studies have addressed the aspects of engineering learning environments that promote the development of self-directed learning abilities. The goal of this study was to identify relationships between students' perceptions of their self-directed learning ability and their learning motivation within a project-based learning environment. Junior engineering students in a test cohort with heavy emphasis on project-based learning completed surveys on self-directed learning aptitude and learning motivation. Responses were compared …

The Theory Of Planned Behavior As A Model Of Academic Dishonesty In Engineering And Humanities Undergraduates, Trevor S. Harding, Mathew J. Mayhew, Cynthia J. Finelli, Donald D. Carpenter

Materials Engineering

This study examines the use of a modified form of the Theory of Planned Behavior in understanding the decisions of undergraduate students in engineering and humanities to engage in cheating. We surveyed 527 randomly selected students from three academic institutions. Results supported the use of the model in predicting ethical decision-making regarding cheating. In particular, the model demonstrated how certain variables (gender, discipline, high school cheating, education level, international student status, participation in Greek organizations or other clubs) and moral constructs related to intention to cheat, attitudes toward cheating, perceptions of norms with respect to cheating, and ultimately, cheating behaviors. …

Collaborative Design Of Project-Based Learning Courses: How To Implement A Mode Of Learning That Effectively Builds Skills For The Global Engineer, Richard N. Savage, Jonathan Stolk, Linda Vanasupa

Materials Engineering

Success for tomorrow’s engineers necessitates the design of curricula that promote awareness of the broader impacts of engineering, enhances systems thinking, reflects sustainable engineering practices, and helps prepare students to make an impact in the global community. Project-based learning approaches that emphasize student learning rather than instructor teaching may be a key to successful development of “global engineers.” Evaluations of project-based courses show increases in student motivation, problem-solving ability, communication and teaming skills, knowledge retention, and capacity for self-directed learning. Despite these reported benefits, curriculum-wide implementations of project-based learning are rare, probably partly due to the traditional emphasis on technical …

A Systemic Model Of Development: Strategically Enhancing Students' Cognitive, Psychomotor, Affective And Social Development, Linda Vanasupa, Jonathan Stolk, Trevor S. Harding, Richard N. Savage

Materials Engineering

The challenges of the 21st century create an imperative for engineering educators: to design learning experiences that result in engineering professionals with a sophisticated level of cognitive, psychomotor, social and affective development. We propose a tool for the design process. Our systemic model of development (SMD) is based on a large body of learning theory and empirical data. It maps the relationships among the major factors that influence learning in the form of a causal loop diagram. To demonstrate the value of the SMD, we compared the motivational profiles of a test group (36 students) who took an engineering course …

Academic Integrity Among Engineering Undergraduates: Seven Years Of Research By The E3 Team, Cynthia J. Finelli, Trevor S. Harding, Donald D. Carpenter

Materials Engineering

The E³ Team (Exploring Ethical decision-making in Engineering) is a group of engineering educators and educational researchers who have worked collaboratively since 2000 to understand the underlying causes of academic dishonesty in engineering undergraduate populations. The team was especially motivated by decades of others’ work showing that, when surveyed, engineering students were among those most likely to report frequently cheating. This paper summarizes some of the team’s more important findings from three major studies that surveyed a total of 1300 engineering and humanities undergraduates at eleven institutions. The paper also describes the next phase of the team’s research and …

Exciting Students About Materials Science And Engineering: A Project-Based, Service-Learning Museum Design Course, Katherine C. Chen

Materials Engineering

A new course was developed for Materials Engineering students to design, create, and install interactive, educational displays on Materials Science & Engineering for a science museum at a local K-6 charter school. The course grew out of an ASM Foundation grant “to excite young people in materials, science, and engineering careers,” and the challenge was put forth to Cal Poly students. A formal design sequence was applied to give the students the opportunity to learn about the design process, project management, and teamwork. User profiles were created for the stakeholders, and project values were established. The class partnered with the …

A Design Methodology For Empowering Project-Based Learning, Richard N. Savage

Materials Engineering

One of our primary objectives is to equip undergraduate engineering students to be successful global engineers, ready to face the challenges of the 21st century. Students need to develop self-directed learning skills, systems level thinking, the ability to integrate principles of sustainability into design solutions and recognize that they serve a global community. Project-based learning (PBL) has been identified as an effective process for developing these skills; however, to be effective, project-based learning activities require a clearly articulated design methodology. Engineering students must learn to recognize the similarities and differences between the scientific and design methods. Both can be looked …

The Mechanical And Thick Section Bending Behavior Of Friction Stir Processed Aluminum Plate, D. Hilbert, C. Fuller, M. Mahoney, B. London

Materials Engineering

Friction stir processing (FSP) 2519-T87 aluminum plate results in enhanced ductility, 25% strain at fracture. However, the yield strength in the FSP zone drops to 175 MPa from ~400 MPa. Actively cooling the plate during FSP increases the yield strength to 185 MPa and decreases ductility to 20% strain at fracture. Thick bending of a plate of the alloy was demonstrated after the surface was subjected to FSP.

Integrating Project-Based Learning Throughout The Undergraduate Engineering Curriculum, Richard N. Savage, Katherine C. Chen, Linda Vanasupa

Materials Engineering

Equipping engineering students with the skills and knowledge required to be successful global engineers in the 21st century is one of the primary objectives of undergraduate educators. Enabling students to practice self-directed learning, to find solutions to design problems that are sustainable and to recognize that they are part of a global community are just of few of our educational goals. Self-directed learning can define an individual’s ability to practice life-long learning. It places the responsibility on the individual to initiate and direct the learning process and can enable an individual to adapt to change. Project-based learning provides the contextual …

Use Of Friction Stir Processing And Friction Stir Welding For Nitinol Medical Devices, Blair London, Murray Mahoney, Alan Pelton

Materials Engineering

Metallic materials may be joined utilizing a friction stir processing technique. The friction stir processing technique utilizes a shaped, rotating tool to move material from one side of the joint to be welded to the other without liquefying the base material.

Work In Progress: Crossing The Engineering Border Into Art And Society With A Materials Selection For The Life Cycle Course, Katherine C. Chen, Blair London

Materials Engineering

A new course in materials engineering has been developed to incorporate industrial design and sustainability principles. Many current engineering tasks require the ability to comprehend and consider the complicated interplay of technology with the environment and society. Thus the changing skill set required of future engineers is being reflected in the changes with our courses. We are stepping beyond the traditional boundaries of engineering courses to present a more holistic approach to problem solving. The use of materials and processing techniques is applied to product design, and thus involves consideration of the end user and the end of product life. …