2007 Project Presentation Day

Mechancial Engineering Department
Materials Science and Engineering

April 17, 2007

Chlorine Free Lubricant Selection in a Coiled Pin Manufacturing Process

Tatiana C. Winey, Ann Troy

This project focused on replacing a chlorinated forming lubricant with a non-chlorinated lubricant for the manufacture of coiled pins. A field of six lubricants was selected based on technical data sheers and ASTM standardized four-ball lubricant performance test results. The lubricants were subjected to a tungsten carbide corrosion test and then tested to determine their ability to form coiled pins during production. Results showed that of the six lubricants tested; only one was able to successfully form the coiled pins.

Advisor: Prof. Richard D. Sisson, Jr.

Heat Treating Aluminum Alloys

Eric Wallhagen

This project examined the effects of aging time and temperature on aluminum 319. The mechanical properties of cast tensile bars were recorded for various heat treatments, and then compared to published standards. The results indicate that aging at 190 86C is an alternative to present T6 heat treating, as better strength was obtained in a shorter tme. Aging at 190 86C achieved peak strength in only 4 hours, whereas aging at 150 86C (T6 standard) peak strength wasn't obtained until 24 hours of aging. Similarly, aging at 230 86C showed an even faster peak, reaching peak strength in only 45 minutes, though the strength after this treatment wasn't as high as the strength after 4 hours at 190 86C. Further experiments should be conducted between 170 and 240 86C to optimize the aging process of aluminum 319.

Advisor: Prof. Richard D. Sisson, Jr.

Grain Coarsening Behavior of two g' Ni-based superalloys

Anthony George, Danielle C. Modeste, Daniel M. Waitt

The aircraft industry has pushed the limits of the physical world and in order to make improvements it has been necessary to create new metals that are able to withstand extreme forces and temperatures. These new metals are known as superalloys. They have been created because the industry requires some metals to have high mechanical strength, be creep resistant, and have high modulus. The most common type of metal that displays these characteristics are nickel based super alloys. These alloys were designed to be able to operate in extreme conditions for example, inside a jet engine. In order for the industry to move forward, it is necessary to have a complete understanding of these new materials. One part of this is to understand how these new materials react when heat treated.

We were asked to study the effects of heat treatment on two superalloys, IN-100 and N-210. More specifically, an experiment was devised that allowed us to compare grain sizes with respect to the way it was heat treated. In order to obtain a better understanding of the effects of the heating on the grain sizes, several combinations of heating rates, temperatures, and dwell times were used. By conducting this experiment, it may be determined that by heat treating these materials their characteristics may be improved. By determining how the grains change due to the different heating curves, it can be determined if the metal can be strengthened through heat treatment. Also, the results will indicate whether the creep resistance can be improved or not.

Advisor: Prof. Richard D. Sisson, Jr.

Nano-Structured Surface Engineering for Biomedical Implants

MQP in Materials Science Award Winner presented by
ASM Worcester Chapter on April 18, 2007

2007 Aerospace & Mechanical Engineering MQP Awards - "Honorable Mention"

Meghan J. Pajonas, Joe Hernandez

Cells react to many chemical, physical and geometric cues within the extracellular environment, a process that can create problems when foreign objects such as medical implants are placed in the body. Poor cell-implant interactions can result in improper implant function or failure. However, clinical investigations have reported that implants manufactured with specific micro-scale surface topographies have shown improvements in cellular adhesion, contact guidance, and tissue integration while controlling apoptosis, macrophage activation. This study proposes that cellular interactions can be controlled by using implants with specifically designed surface characteristics.

The difficulty of fabrication and costs associated with commonly used nanofabrication methods hinders progress in these types of studies. However, this study employed a sophisticated electrochemical anodization fabrication technique to produce templates with uniform nano-sized features. The low costs and ease of production associated with this manufacturing technique are important advantages to future commercial applications of this production method. Anodized aluminum oxide (AAO) templates with highly-ordered nanopore structures were used as substrates to examine the influence of surface characteristics on cellular adhesion. AAO templates were coated with alkanethiol based (terminal groups -CH3, -OH, and -COOH) self-assembled monolayers (SAMs) as well as a calcium-phosphate mixture. The coated implants were then put in contact with osteoblasts so that implant-cell interactions could be examined. Osteoblast adhesion to the template surfaces was examined and the results were quantified, allowing optimum surface characteristics to be determined.

Advisor: Prof. Jianyu Liang

Effects of Rotational Speed on the Diameter and Alignment of Electrospun Fibers

2007 Aerospace & Mechanical Engineering MQP Awards - "Honorable Mention"

David Greene, Tom Regan

The production of electrospun nanofibers drawn out onto a dynamic surface is expected to align along the axis of rotation of the collecting drum. For this study, a 0.04 g/mL solution of Polystyrene and N, N - Dimethylformamide was electrospun onto rolls of aluminum foil in such a way that a continuously new surface was provided. Single fibers spanning the length of the collecting surface were created. Resulting fibers were characterized for changes in mean fiber diameter at a range of collecting speeds (0-220 inches per minute.)

Advisor: Prof. Satya Shivkumar

Students working on their Projects

David Greene, Tom Regan	Eric Wallhagen	Ann Troy, Tatiana Winey

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Last modified: May 01, 2007, 15:56 EDT