Transport Phenomena In Aluminum Oxide

This text provides a teachable and readable approach to transport phenomena (momentum, heat, and mass transport) by providing numerous examples and applications, which are particularly important to metallurgical, ceramic, and materials engineers. Because the authors feel that it is important for students and practicing engineers to visualize the physical situations, they have attempted to lead the reader through the development and solution of the relevant differential equations by applying the familiar principles of conservation to numerous situations and by including many worked examples in each chapter. The book is organized in a manner characteristic of other texts in transport phenomena. Section I deals with the properties and mechanics of fluid motion; Section II with thermal properties and heat transfer; and Section III with diffusion and mass transfer. The authors depart from tradition by building on a presumed understanding of the relationships between the structure and properties of matter, particularly in the chapters devoted to the transport properties (viscosity, thermal conductivity, and the diffusion coefficients). In addition, generous portions of the text, numerous examples, and many problems at the ends of the chapters apply transport phenomena to materials processing.

Fully comprehensive introduction to the rapidly emerging area of micro systems technology Transport Phenomena in Micro Systems explores the fundamentals of the new technologies related to Micro-Electro-Mechanical Systems (MEMS). It deals with the behavior, precise control and manipulation of fluids that are geometrically constrained to a small, typically sub-millimeter, scale, such as nl, pl, fl, small size, low energy consumption, effects of the micro domain and heat transfer in the related devices. The author describes in detail and with extensive illustration micro fabrication, channel flow, transport laws, magnetophoresis, micro scale convection and micro sensors and activators, among others. This book spans multidisciplinary fields such as material science and mechanical engineering, engineering, physics, chemistry, microtechnology and biotechnology. Brings together in one collection recent and emerging developments in this fast-growing area of micro systems Covers multidisciplinary fields such as materials science, mechanical engineering, microtechnology and biotechnology, et al Comprehensive coverage of analytical models in microfluidics and MEMS technology Introduces micro fluidics applications include the development of inkjet printheads, micro-propulsion, and micro thermal technologies Presented in a very logical format Supplies readers with problems and solutions

The ignition phenomena that can occur during the reaction-bonding of aluminum oxide is investigated. It is experimentally characterized through measurements of the combustion temperature and the velocity of the ignition front. One- and two-dimensional, transient, simultaneous material and energy balances are used to model the phenomena in a cylindrical geometry. The models are used to predict the aluminum concentration, oxygen concentration, and temperature distributions as a function of time during ignition. Thermal explosion analysis is utilized to predict the conditions under which samples will ignite, and to calculate furnace temperature programs that will avoid ignition. The aluminum concentration and temperature distributions are used to estimate the elastic stresses that are developed during ignition. Feedback control is applied to the reaction-bonded aluminum oxide system with great success. The heating rate is adjusted automatically based on the reaction rate, measured through differential thermogravimetry. Adjusting the furnace temperature in this way is more reliable and allows the sample to react in a slow and controlled manner, avoiding ignition and cracking altogether. Criteria based on heat transfer and oxygen diffusion considerations are developed to determine the reaction rate set-point, and simplify the process of reaction-bonding considerably.