Twinning Phenomena along and beyond the Bain Path

Abstract

Twinning is a phenomenon that occurs, e.g., during deformation, martensitic transformation and film growth. The present study shows that the crystallography of twinning can be described by two twinning modes along the complete Bain transformation path and beyond connecting body-centered and face-centered cubic structures. To probe this concept, we used strained epitaxial films of the Fe-Pd magnetic shape memory system. As the substrate acts as an absolute reference frame, we could show by pole figure measurements that all observed twinning can be a body-centered and face-centered cubic twinning mode. This continuously transforms towards identity when approaching the complementary structure.

Growth, microstructure and thermal transformation behaviour of epitaxial Ni-Ti films

“…In addition to the high intensity signals at Ψ = 45 • and Φ = n • 45 • marked by black squares, which originate from the epitaxially grown NiTi, further signals with intensities lower than 1 % of the main signals are observed, which become visible only in the logarithmic scale used. To further understand the origin of these lower intensity signals, simulations of pole figures were carried out, following the procedure outlined in [23]. Using the substrate as an absolute reference frame, the pole figure simulations predict signals as depicted in the left quadrant in Fig.…”

“…To further understand the origin of these lower intensity signals, simulations of pole figures were carried out, following the procedure outlined in [23]. Using the substrate as an absolute reference frame, the pole figure simulations predict signals as depicted in the left quadrant in Fig.…”

Akıllı Malzeme Şekil Hafızalı Alaşımların Termodinamiği

“…denge durumunda ΔG = 0 olduğundan, ΔH = TΔS ve böylece ΔS = ΔH/T 0 (25) ΔG = ΔH -(T ΔH/T 0 ) = ΔH(T 0 -T Ms )…”

“…Bain bu model de kristal örgünün martensitik dönüşüm sırasında belli bir deformasyona uğradığını iddia etmiştir. Bu modele göre yüzey merkezli kübik yapıya (fcc) sahip atomların komşulukları değişmeden, atomlar arası uzaklıkların değişmesi sonucunda hacim merkezli kübik (bcc) veya hacim merkezli tetragonal (hct) yapılara dönüşebilirler (Şekil 4)[23][24][25].…”

Structural, Wetting and Magnetic Properties of Sputtered Fe70Pd30 Thin Film with Nanostructured Surface Induced by Dealloying Process

“…The chemical composition of the FePd binary alloy system strongly influences its structure and magnetic properties allowing the use in a variety of applications [ 21 , 23 , 24 , 25 , 26 ]. These properties include magnetic shape memory effect for the Fe 70 Pd 30 alloys [ 27 , 28 , 29 , 30 , 31 ], high perpendicular magnetic anisotropy for Fe 50 Pd 50 [ 32 , 33 ], as well as hydrogen absorption characteristics for the palladium-rich FePd material [ 34 , 35 ], catalytic activities [ 36 , 37 ] and SERS devices [ 26 ].…”