Time: 10:50 a.m.
Place: TMS 2013, San Antonio, USA
Umut Salman, Harvard School of Engineering and Applied Sciences,, Cambridge, USA
Alphonse Finel, Laboratoire d'etude des microstructures ONERA, Châtillon, France
We present a theoretical study of the microstructure formation in NiTiCu and NiTi shape memory
alloys during the cubic (B2) to orthorhombic (B19) and cubic (B2) to monoclinic (B19') martensitic phase transformations, correspondingly. We provide a simple Landau type free energy functional for cubic-to-orthorhombic and cubic-to-monoclinic phase transformations which is capable to reproduce elastic properties of the NiTiCu and NiTi SMA in a temperature range wider than (Af – Mf) around the transformation temperature. This allows to effectively study microstructure formation during the temperature induced martensitic phase transformation in NiTiCu and NiTi shape memory alloys. The proposed functional is used for the three dimensional microstructure formation simulations using the Lagrangian dynamics modeling. A detailed analysis of the obtained microstructures is provided, which explains some of the experimentally observed phenomena.