Title of article :
The influence of temperature on lattice parameters of coexisting phases in NiTi shape memory alloys—a neutron diffraction study
Author/Authors :
Khalil-Allafi، نويسنده , , J. and Schmahl، نويسنده , , W.W. and Wagner، نويسنده , , M. and Sitepu، نويسنده , , H. and Toebbens، نويسنده , , D.M. and Eggeler، نويسنده , , G.، نويسنده ,
Abstract :
NiTi shape memory alloys were investigated by Rietveld refinement of neutron diffraction data at various temperatures. For an aged sample of nominal composition Ni50.7Ti49.3 at 294 K, B2 austenite, R-phase, and Ni4Ti3 precipitates coexist, and the Rietveld refinement provides accurate lattice parameters for the phases in this microstructure. The observed rhombohedral shape deformation occurring with the formation of Ni4Ti3 and R-phase in the B2 matrix is similar in magnitude and of opposite sign. Thus the strain field around a Ni4Ti3 precipitate can be compensated by a single variant of R-phase.
Keywords :
Phase transformation , NiTi shape memory alloys , Rietveld method , Ni4Ti3 , Lattice Parameter , Coherency strain
Journal title :
Astroparticle Physics
