Structural stabilities, elastic constants, generalized stacking fault energetics, and the martensitic transformation mechanisms for the Ni50−xTiPtx (x = 0 − 30) ternary system: ab initio investigation

Free access article

Issue		ESOMAT 2009 2009


Article Number		02010
Number of page(s)		7
Section		Principles, Simulations, Materials: Background
DOI		http://dx.doi.org/10.1051/esomat/200902010
Published online		01 September 2009

ESOMAT 2009, 02010 (2009)
DOI: 10.1051/esomat/200902010

Structural stabilities, elastic constants, generalized stacking fault energetics, and the martensitic transformation mechanisms for the Ni_50−xTiPt_x (x = 0 − 30) ternary system: ab initio investigation

N. Hatcher¹, O. Yu. Kontsevoi¹ and A. J. Freeman^{1, 2}

¹ Department of Physics and Astronomy, Northwestern University, Evanston, Illinois 60208, USA
² Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA

n-hatcher@northwestern.edu

Published online: 1 September 2009

Abstract
To determine the effect of ternary additions on the martensitic behavior of NiTi, we apply ab initio calculations using the highly precise full-potential linearized augmented plane wave method to the Ni-Ti-Pt system. We compare formation energies of various stoichiometries and the pair energetics between Pt atoms to create a numb er of model austenite structures, finding that Pt atoms prefer to decorate the lattice at third nearest neighbors from one another, and establish the hierarchy among the austenitic and martensitic phases. We examine the structural stability to determine the susceptibility toward displacive phase transformation: namely, we calculate planar generalized stacking fault energetics of major shear planes including the {100}, {011}, and {111} planes and we calculate and compare the elastic constants of each phase. We show that increased Pt content causes a dramatic softening of the austenite C′ elastic constant and increased rigidity in the martensite, and there is a high resistance to {100} shear similar to equiatomic NiTi. Finally, we explore a martensitic mechanism of this alloy and explain how the transformation path and energy barriers of the NiTi system are affected by Pt.

What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.