AddThis Social Bookmark Button

Google
Web www.calphad.com












AddThis Social Bookmark Button

Google
Web www.calphad.com

Glossary

Thermodynamics

Historically, the science of thermodynamics was developed to provide a better understanding of heat engines, with particular reference to the conversion of heat into useful work. Lord Kelvin invented the name thermodynamics to direct attention to the dynamic nature of heat, as the term implies a field concerned with the mechanical action produced by heat. Although the applications of the science are much broader (e.g., in chemistry, metallurgy, materials science, geology, etc.), the name has remained.

Thermodynamics is an empirical and phenomenological physical science concerned with the transfer of heat and the appearance and disappearance of work attending various conceivable chemical and physical processes. Since it is a discipline that supplies science with a broad array of relationships between the properties that matter exhibits as it changes its condition, it plays an essential role in metallurgical engineering and materials science. Thermodynamics is, therefore, concerned with the behavior of matter, where matter is anything that occupies space. By applying the laws and principles of thermodynamics it is, for example, possible to predict whether or not a particular chemical process can take place under any given conditions. Also, formulae and laws discovered experimentally can be derived theoretically.

The value of thermodynamics lies, therefore, in the fact that these laws and certain accompanying definitions have been given mathematical expression. This has led to the development of a consistent network of equations from which a wide range of practical results and conclusions may be deduced. In order to apply the thermodynamic method, however, it is necessary to develop the ability to proceed logically from one deduction to the next, always making use of precisely defined terms.

Thermodynamics has derived from two relatively simple observations: that heat and work are two different forms of energy and that heat flows from a hot body to a cold body. These two observations are simplified versions of the first law of thermodynamics and the second law of thermodynamics.

In thermodynamics there is always a system, which can be closed or open for exchange of matter, heat, and work with its surrounding. A thermodynamic system is made up of components and phases.

In a system, the matter will always appear in one or more stable or meta-stable phase (a homogeneous part of the system). A homogeneous system is uniform in composition, temperature, and pressure, and has the same structure everywhere. A heterogeneous system consists of at least two phases.

Thermodynamics deals with systems that are in a state of equilibrium. There are two types of state variables that describe a system in thermodynamic equilibrium: extensive and intensive.

Consulting Services

To cover the costs of running this site, we accept consulting assignments to perform customer tailored Thermo-Calc and DICTRA calculations. If we cannot solve your problem, we will help you find at least one organization which has the right human and computational resources to address your specific needs.

We offer a money back guaranty for our consulting services if you are not satisfied. Drop us a line; our e-mail address is: info@calphad.com.