Mechanical Engineering Department
Materials Science & Engineering

Seminars 2003-2004

Welcome New Graduate Students

Thursday, September 4, 2003, 12:00 Noon, Washburn 323

Presented by:

Prof. Richard D. Sisson, Jr.

Abstract

Fall luncheon held to introduce the new graduate students to present graduate students, faculty and staff. Professor Sisson outlined the upcoming seminars and present projects that are being researched in our labs. He gave a synopsis of what research has taken place in the Metal Processing Institute, Biomaterials Laboratory, Center for Heat Treating Excellence, Alternative Fuel Economics Laboratory, and the Scanning Electron Microscope Laboratory.

Laboratory Safety

Thursday, September 11, 2003, 12 Noon, Washburn 323

Presented by:

David Messier, Manager of Environmental and Occupational Safety

Abstract

This seminar will focus on understanding the importance of basic laboratory safety and the fundamentals of hazardous waste management. Topics to be covered include an overview of responsibilities, both for the lab worker and WPI, chemical storage practices, engineering controls, personal protective equipment and emergency response procedures.

Fuel Cells --- What will It Take?

Thursday, September 18, 2003, 12:00 Noon, Washburn 323

Presented by:

Prof. Isa Bar-On

Abstract

Fuel Cells hold many promises: lower emissions, less resources used, the possibility to use multiple fuels, etc. What will it take to make fuel cells 'work' economically, socially, and how will we access the environmental impact?? Or what will be the social and economic costs??? In this talk we will present an overview of some of the research of the AFEL.

A Metallurgical Examination and Simulation of the Oxidation and Sulfidation of the World Trade Center Structural Steel

Thursday, September 25, 2003, Washburn 323, 12:00 Noon

Presented by:

Erin Sullivan

Abstract

To simulate the extreme wastage experienced by WTC building 7 structural steel during the fires experienced on September 11, 2001, A36 steel was reacted with powder FeS/FeO/SiO2/C in an open air furnace environment at 900C and 1100C. Initial investigations of the WTC structural steel revealed an apparent liquid "slag" attack and penetration down grain boundaries by liquid iron oxides and sulfides. The current laboratory simulation results show grain boundary penetration by a liquid slag at higher temperatures regardless of powder reactants applied to the steel samples. Eutectic structures within the Fe-S-O and Fe-Si-O systems were observed along with elemental segregation within the near surface microstructure. In all cases, grain boundary penetration appears to be strongly influenced by the addition of alloying elements and contaminants.

Analysis of the Cause of the Severe Erosion Damage Observed in Structural Steel Components from the 9/11 World Trade Center Incident

Thursday, October 9, 2003, 12:00 Noon, Kinnicutt Hall

Presented by:

Prof. Ronald Biederman
George F. Fuller Professor of Mechanical Engineering

Abstract

Several Steel samples from Buildings 7, 1 and 2 of the World Trade Center were collected during the Federal Emergency Management Agency forensic investigation shortly after the September 11, 2001 incident. Macroscopically the steel samples supplied had severe "erosion" with plate thickness varying from 12.7mm to a total loss of metal in many areas. Also, some localized plastic deformation was observed. A determination of the cause of this unexpected erosion and an estimate of the maximum temperature that this steel likely experienced will be present along with a perspective on the implications that this damage may pose for high rise structural steel buildings.

Evolution of Microstructure During Solidification of Al-Si Cast Alloys: Recent Advances

Thursday, October 30, 2003, 12:00 Noon, WB 323

Presented by:

Sumanth Shankar
Research Scientist
Advanced Casting Research Center (ACRC)
Metal Processing Institute, MPI

Abstract

The continuing quest for aluminum castings with enhanced mechanical and physical properties for applications in the automotive and aerospace industries has intensified the interest in aluminum - silicon alloys. Consequently, in the past decade, one of the main research emphases at the Advanced Casting Research Center has been the understanding, quantification, and tailoring of the microstructure of these casting alloys to obtain alloys with better casting characteristics and overall service performance. There are two important stages of microstructure development during the solidification of Al-Si alloys. These are nucleation of the primary phase at, or slightly below, the liquidus temperature of the alloy, and microstructure development during freezing in the mushy (solid + liquid) zone. This presentation will bring to you the latest developments in techniques of microstructural analysis that has aided us in better understanding the mechanisms involved in the development of Al-Si cast microstructure. A better understanding of the mechanism is certainly paving ways to development of alloys with superior properties. The main topics that will be covered are as follows:

Evolution of the primary proeutectic phase
- Grain refining of proeutectic phase
- Control of size and morphology of proeutectic phase
Evolution of phases during mushy zone solidification
- Evolution of eutectic phases
- Control of size and morphology of eutectic phases

A lot of new and useful metallographic and microscopic techniques shall be discussed.

Operating Mechanisms During Dynamic Loading of Aluminum Cast Components

Thursday, November 6, 2003, 12:00 Noon, Washburn 323

Presented by:

Diana Lados, MTE Graduate Student

Abstract

Due to the increasing use of cast aluminum components in automotive and aerospace applications that involve cyclic loading, the fatigue characteristics of aluminum castings have become of great interest. However, and despite the extensive research efforts dedicated to this topic, a fundamental and mechanistic understanding of the behavior of these alloys when subjected to dynamic, cyclic loading is still lacking. This research work was geared towards establishing the mechanisms that are active at the microstructure level during dynamic loading and failure of Al-Si-Mg alloys. The role of the alloys major constituent phases, a-Al dendrites and Al/Si eutectic phase, on the fatigue crack growth response was mechanistically investigated to develop a fundamental understanding of the alloys microstructural features when related to fatigue resistance in cast aluminum alloys. The impact of microstructure on crack's early stages (?Kth) as well as crack propagation regimes (Paris region) was evaluated for alloys of different Si composition, grain size level, and heat treatment. In addition a complex analysis of the Linear Elastic Fracture Mechanics (LEFM) and Elastic-Plastic Fracture Mechanics (EPFM/J-integral) approaches was performed in order to evaluate their applicability to ductile alloys and delineate the validity boundaries for LEFM. The importance of residual stress-microstructure interactions will also be discussed.

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