Solidification Thermo-Mechanics

This research focuses mostly on those aspects of solid mechanics pertaining to the contact of deformable bodies and particularly to situations in which non-uniform temperatures result from heat flow across it. In such cases, thermo-elastic deformation of the contacting bodies modifies the contact pressure distribution and can lead to a rich variety of phenomena including localization and dynamic instabilities. These effects are of considerable technological importance, including, for example, non-uniform contact pressure, high local temperatures and heat fluxes in solidification of castings: a phenomenon known as Thermo-elastic Instability (TEI). Casting is an important and widely used manufacturing process. The generation of residual stresses and deformation during the process leads to form errors in the finished product and hence to the need for expensive additional machining processes. The recent research mostly seeks to enhance the knowledge about this process by applying rigorous applied mechanics methods to suitably idealized models. In particular, by focusing on the effects of thermal and thermo-elastic conditions at the mold-casting interface on the development of non-uniformities in the finished casting, the research provides guidance on the conditions required to minimize profile errors.



Freezing front growth instability in immersion casting



The results of this work on solidification thermo-mechanics will be more readily transferred to the casting industry. It should also be noted that some of these research activities on solidification thermo-mechanics were funded by NSF (National Science Foundation, USA), ALCOA (Aluminium Company of America, USA) and SABIC (Saudi Basic Industries Corporation, Saudi Arabia) in the past, and have already been used to improve the design of solidification processes. This research is also relevant to automotive industry since TEI problems are particularly prevalent in energy dissipation systems such as breaks and clutches. The methods used to develop models for the solidification process can easily be modified for TEI analysis of breaks or clutches.




Critical wavelength effect on position of gap nucleation along the mold-shell interface



Faruk Yigit, Professor