IET is a research organization in measurement, heat transfer and materials science. IET is affiliated with the National Academy of Sciences. Research works involve simultaneous interdisciplinary efforts from experimentalists, physicists and metallurgists (i.e. materials scientists).
The areas in research are:
- Inverse problem methodical development and its
applications to determine parameters of heat transfer
- Interfacial heat transfer coefficient
- Thermal conductivity of
- Experimental measurement of thermal properties
- Enthalpy-related properties
- Thermal conductivity
- Surface tension
- Process metallurgy
- Flow behaviour of molten metals
- Solidification processing of metallic alloys
- High-temperature chemical processing of materials
- Mathematical modelling and computation
Find below an outline of the research areas, and further information.
Thermo-Prop software: The database called "Thermo-Prop" computer programme can be said to be the outcome of extensive work carried out on the development of sound, accurate, experimentally and physically based models for materials properties. Wide ranging data are available such as Fe-, Cu- and Al-base alloys which also include more detailed information concerning fraction solid, density and thermal conductivity change in the mushy zone that intrinsically occur during solidification.
For example, the thermophysical and physical properties of the liquid and solid phases are critical components in casting simulations. Such properties include the fraction solid transformed, enthalpy release, thermal conductivity and density, all as a function of temperature.
The database is well established as the leading source of information on materials properties; thus it provides a strong platform for thermophysical and physicochemical properties needed in process modelling.
The subroutine "Heat Transfer" of Thermo-Prop software adopts inverse anaysis techniques to determine the interfacial heat transfer coefficient at metal/mould interface or at boundary between two heat-conducting media
- IET develops measurement methods to determine the
thermophysical data (heat capacity, density, and viscosity) needed for models to describe industrially important processes such as casting, rolling and forging.
Process metallury projects always encompass:
- Flow behaviour of molten metallic materials.
- Thermal effect during solidification processing of metallic alloys.
- High-temperature chemical processing of materials.
Flow behaviour of molten metallic materials:
Computer modelling of high temperature proceses such as metal casting, primary and secondary melting, spraying, and welding is now a part of modern production routes.
Benefits include improvements in:
- process design and control
- product quality
- the use of energy
- "getting it right first time"
Process models that simulate fluid flow need reliable and accurate thermophysical data for commercial alloys.
Thermal effects during solidification processing of metallic alloys.
The increasing use of mathematical modelling in simulating manufacturing processes demands reliable and accurate data for the thermophysical properties involved.
IET develops techniques for measuring the enthalpies of commercial alloys up to 1700 °C under cooling conditions comparable to those in industrial castings. Work is also carried out to measure the thermal conductivities of commercial alloys at temperature up to 1650 °C. The electrical resitivities of commercial alloys are determined to provide values for the thermal conductivity of the two-phase solid/liquid ("mushy") zone. Methods are also available for measuring the thermal conductivies of mould materials used in industrial practice through inverse technique.
High-temperature chemical processing of materials
Applying a knowledge of chemical thermodynamics to the modelling of high-temperature processes offers the manufacturing industry an inexpensive, efficient method of exploring a potential range of compositions and processing conditions. The accuracy of such predictions, however, inevitably relies on the quality of the data used in the calculations.
A recent survey on the availability of critically assessed data related to high temperature processes and recycling has shown that while there has been a growth over the last few years in thermodynamic databases containing high quality data, there are still many gaps which inhibit their widespread use in materials processing and recycling. Surveys have also shown that there is a growing need for equivalent databases containing chemical diffusion data, which represent how individual elements migrate.
Research is being undertaken to develop new experimental techniques to measure chemical diffusion properties of important industrial systems in order to provide the information necessary for developing such databases. Chemical diffusion data for aluminium-base alloys, copper-base alloys and steels are now available.
|Heat and mass transport modelling in multi-material systems
- Transport modelling: The speed at which heat or mass is transferred through a material is of great importance to engineers and manufacturers. Depending on the application it may be desirable to have a slow transfer of heat, for insulating purposes, or a fast transfer of heat, for increased productivity in molding applications or for higher efficiency heat exchangers. Mass diffusion is important in such processes as moisture permeability of paint films or the degradation of the matrix in polymer composite laminates and some packing material. Plastic products are increasingly being made as layered designs so the manufacturer has the freedom to tailor the products properties to a particular application.
To better understand how a material is thermally performing under service conditions or during manufacturing it is desirable to use modelling and visualisation techniques to predict the material respose. Transport modelling refers to the modelling of heat and mass transfer as both are considered as transport processes that originate from molecular activity. Heat transfer is initiated by a temperature difference in a medium while mass transfer is initiated by a difference in the concentration (chemical potential for more complex systems with stress gradients) of some chemical species in a mixture.
- Inverse analysis: Inverse analysis is required when parameters for the direct model are unknown and therefore need to be estimated by "fitting" the model to experimental data. The fitting process may be done computationally by using optimisation routines to determine a parameter or a combination of parameters from repeated runs of the model.
Development of inverse modelling software has been highlighted as an important tool for industry to help with obtaining parameters for commercial finite difference or finite element software, aiding the design of new products and improving efficiency in the manufacturing process.
The subroutine "Heat Transfer" of Thermo-Prop software has been specifically developed at IET for casting applications which require inverse modelling of multi-material systems, subjected to transient heat transfer. Thermo-Prop has the capability to model multi-directional arrays and adopts inverse modelling techniques using optimasation methods to reliably determine material and model parameters. These methods have been applied to a range of problems including; determining unknown thermal properties by minimising multi-parameter fits to experimental data and analysing heat transfer at a boundary between two media. The subroutine "Heat Transfer" can be tailored to specific industrial applications such as polymer processing, heat exchanger, etc.