Materials Science & Technology 2011 Conference & Exhibition
October 17-21, 2011
Danielle Belsito, Yuan Xu, Chang-Kai (Lance) Wu
Diran Apelian, Diana Lados, Makhlouf Makhlouf, Jianyu Liang
Material Recovery and Recycling - Not an Option, But a Prerequisite for a Sustainable Future
Abstract: Material resources are finite and it requires technological innovations as well as governmental policies. Inorganic materials are non-renewable; one would expect that appropriate design, life-cycle analysis, judicious material selection as well as recovery and recycling be the keystones of a new paradigm. The status quo is not sustainable. While significant progress has been made in this area, the industry faces several challenges: (i) upgrading versus downgrading of scrap via intelligent sorting and recycling; (ii) designing recycling processes that are more energy efficient; (iii) develop alloy compositions “designed for recycling”; (iv) incorporating life cycle analysis during the design stage; and (v) end of life dismantling incorporating a “cradle-to-cradle” philosophy in product design and development. This presentation will provide a perspective on these developments with a special attention to meeting societal challenges of the 21st century reviewed from three perspectives: Education; Policy; and Technology.
Innovative and Integrative Materials and Processing: The Key to an Energy-Efficient and Low-Carbon Future
Diana A. Lados
Abstract: Our world faces significant and urgent challenges in meeting future energy needs. Increasing economic growth will require efficient and economical production, distribution, and end-use of energy. At the same time, escalating concerns about global climate change are pushing companies and governments to take immediate action towards significant carbon emissions reductions. Materials Science and Engineering (MSE) has a pivotal and ubiquitous role in meeting these challenges. Innovative materials and their manufacturing processes are critical to achieving the objectives of an energy-efficient and low-carbon world, both in terms of their integral impact on cost-effective renewable and non-renewable energy technologies, as well as the greenhouse gas impact of large-scale manufacturing processes themselves. Recent studies identified specific MSE areas that have the greatest potential impact in both near- and long-terms, while developing R&D innovation roadmaps in these opportunity areas. These developments will be reviewed and discussed, together with examples of related research at WPI.
The Feasibility of Manufacturing Nanocomposite Materials by Introducing Nano-sized Titanium Carbide Particles into Molten Aluminum Alloys
Abstract: The study reported herein assesses the feasibility of manufacturing aluminum-titanium carbide (Al-TiCp) nanocomposite materials by introducing nano-sized titanium carbide particles into a specially formulated molten aluminum alloy. The main issues encountered when attempting to incorporate nano-sized TiCp into molten aluminum result from the poor wettability of TiCp by aluminum and the high surface tension of aluminum. It is shown that KAlF4 can mitigate these difficultieswhile reducing the tendency of the nano particles to cluster. It is also shown that the presence of Mg in the alloy enhances incorporation of the nano particles into the molten alloy by decreasing the alloy’s viscosity and surface tension. Another difficulty arises from the high tendency of nano-sized TiCp to oxidize when they are exposed to the elevated temperature of the melt. It is shown that introducing the particles underneath the melt’s surface mitigates their tendency to oxidize and facilitates their incorporation into the alloy.
A Novel Method for Manufacturing Aluminum-Aluminum Nitride Nanocomposites
Abstract: Aluminum matrix composites with aluminum nitride particle reinforcement are attractive engineering materials for many automotive and aerospace applications because of the many desirable characteristics of AlN. The attractive properties of Al-AlN composites may be further enhanced by scaling the size of the AlN particles down to the nano range. Unfortunately, the potential for improved composite properties with decreasing size of the AlN is often compromised by an increased tendency towards clustering and uneven dispersion of the particles in the alloy. In this publication we present a novel manufacturing process in which the AlN are synthesized in-situ within an aluminum alloy by means of a controlled gas-liquid reaction to produce an aluminum matrix composite wherein submicron AlN are homogeneously dispersed. Also, we present the mechanism of formation of the AlN particles and we discuss the effect of the composition of the matrix alloy on the efficiency of the aluminum nitridation reaction.
An Integrated Heat Treatment Model for Cast Aluminum Alloys
Chang-Kai (Lance) Wu
Abstract: An integrated mathematical model is being developed to allow predicting the response of aluminum alloy cast components to heat treatment. The model takes into account all three stages of the typical T6 heat treatment; i.e., the solutionizing, quenching, and aging stages, and when complete, it will allow predicting the local hardness and room temperature mechanical properties within a cast component, as well as the magnitude of residual stresses and overall dimensional changes that may be induced by the heat treatment. The mathematical model, which may be programmed into the commercially available finite element solver ABAQUS, uses a Quench Factor Analysis together with the Shercliff and Ashby Aging Model and a database that includes the temperature-dependent mechanical, physical, and thermal properties of the alloy. Also the model uses the temperature-dependent heat transfer coefficient for each one of the three stages of the heat treatment regimen. In this publication, we report on the measurements that produce the database and the heat transfer coefficients. In its current stage of development the model can accurately predict hardness; therefore in this publication we only compare measured values of hardness to their model-predicted counterparts. However, we also present details of the ongoing work that will eventually extend the model to allow predicting mechanical properties, residual stresses, and overall dimensional changes. Comparisons of measured values of these characteristics to their computer-predicted counterparts will be presented in future publications.
Integrated Computational Materials engineering: Modeling and Simulation Applied to Metals Processing
Abstract: Software has been developed to model the carbonitriding heat treating process. This model uses the finite element method to simulate the absorption and diffusion of carbon and nitrogen into several steels. The diffusional interactions between carbon and nitrogen have been experimentally and theoretically determined and are included in the model. It was found that low concentrations of nitrogen increase the effective diffusivity of carbon in steel. These experimental results will be presented along with the beta version of the validated model. The effects of carbon potential and ammonia concentration (nitriding potential in the endogas atmosphere will also be presented a discussed.
October 22, 2011