John F. Maguire

The interphase in adhesion : bridging the gap

Abstract This paper addresses the origin, structure and properties of the interphase in adhesion. By interphase is meant that interfacial region between bulk adhesive and bulk adherend over which the local density displays a spatial gradient. In such a region all the local thermodynamic properties, including the mechanical properties, will be a function of distance from the surface. The question of how large these variations may be both in terms of magnitude and range is clearly a matter of some import in adhesive technology. The term “local” is a key consideration because meaningful discussion of the interphase can hardly be contemplated without explicit recognition that matter in the interphase should be regarded properly as existing in a thermodynamically metastable small system of low dimensionality. The results of a number of our numerical and theoretical studies, namely molecular dynamics simulation of realistic interfaces and nonlinear dynamical analysis, have been used to investigate the nature of...

Process Models for Interfacial Matter

Abstract Materials transformation models are essential in the development of artificial intelligence for real-time control of materials processing. The quality of the machine-based decision making process depends critically on the degree to which such models capture the essential attributes of the physico-chemical transformation. In developing process models, the current state-of-the-art is to incorporate relevant source terms (e.g., chemical kinetic or thermal) into a diffusion-like equation while taking into account additional terms representing material or radiation transport. In this paper, it is shown that the above approach is inadequate in the processing of material systems which are not at the thermodynamic limit. A systematic approach to refinement of the models for small systems is presented. Such “small” systems include important applications such as superconducting thin films and materials processing in space-based microgravity environments. The latter will be of particular importance in that exploitation of the unique advantages of microgravity will require remote intelligent process controllers.

An Intelligent Real-Time System for Polymer and Composite Processing

Abstract This paper describes the development of a rule-based artificial intelligence system for processing polymeric materials and components fabricated from advanced polymeric composites. The system integrates three key elements, namely, materials and process sensors, detailed chemical kinetic mathematical models of the physico-chemical aspects of material transformation, and an equipment control module. The equipment control module has been written using CLIPS (C-language Integrated Processing System) and, in addition to interpreting the sensor and model-based information, in real time it uses heuristic reasoning approaches to take into account high cost, low probability events which can occur in manufacturing. The system has been tested in manufacturing and has demonstrated up to fifty percent reductions in process time.