Home

SS DTA™ is a specialized thermal analysis technique that can be used in situ to determine phase transformation behavior in the weld metal and heat-affected zone. It can also be used to determine phase transformation temperatures during actual and simulated heat treatment and for the development of CCT diagrams.

Most of the available phase transition data in engineering materials is generated by the traditional techniques of differential thermal analysis (DTA), differential scanning calorimetry (DSC), and dilatometLimited_processry (DA). DTA and DSC measure the enthalpy variations by comparing the heating and/or cooling thermal history in the tested material to a reference thermal history that is generated by an inert standard that does not undergo any phase transformations. These techniques are highly sensitive to the phase transformations and structural changes in engineering materials. They utilize specialized equipment that is limited to relatively low heating and cooling rates and is not applicable to simulate most of the actual materials processing conditions. Dilatometry measures the volume changes in materials that are associated with solid-state phase transformations. It is insensitive to transformations that cause small (or no) volume changes such as precipitation, recrystallization, and ferromagnetic-to-paramagnetic transition even though these transformations are accompanied by thermal effects. DA is inapplicable in situ (during actual materials processing) and is generally limited in terms of heating and cooling rates by the simulation device that is used in conjunction with DA.The limitations of these methods restrict the availability of phase transition data for the response of engineering materials to non-equilibrium thermal processing. The limitations of each method are displayed to the right.

 

Alexandrov, Boian T., Dr., and John C. Lippold, Dr,. “In Situ Determination of Phase Transformations and Structural Changes During Material Processing.” In-Situ Studies with Photons, Neutrons and Electrons Scattering. Berlin, Heidelberg: Springer-Verlag, 2010. 113-31. Print.