|   | 
Details
   web
Records
Author Salman, O.U.; Finel, A.; Delville, R.; Schryvers, D.
Title The role of phase compatibility in martensite Type A1 Journal article
Year (down) 2012 Publication Journal of applied physics T2 – 22nd International Symposium on Integrated Functionalities (ISIF), JUN 13-16, 2010, San Juan, PR Abbreviated Journal J Appl Phys
Volume 111 Issue 10 Pages 103517
Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
Abstract Shape memory alloys inherit their macroscopic properties from their mesoscale microstructure originated from the martensitic phase transformation. In a cubic to orthorhombic transition, a single variant of martensite can have a compatible (exact) interface with the austenite for some special lattice parameters in contrast to conventional austenite/twinned martensite interface with a transition layer. Experimentally, the phase compatibility results in a dramatic drop in thermal hysteresis and gives rise to very stable functional properties over cycling. Here, we investigate the microstructures observed in Ti50Ni50-xPdx alloys that undergo a cubic to orthorhombic martensitic transformation using a three-dimensional phase field approach. We will show that the simulation results are in very good agreement with transmission electron microscopy observations. However, the understanding of the drop in thermal hysteresis requires the coupling of phase transformation with plastic activity. We will discuss this point within the framework of thermoelasticity, which is a generic feature of the martensitic transformation. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4712629]
Address
Corporate Author Thesis
Publisher American Institute of Physics Place of Publication New York, N.Y. Editor
Language Wos 000305363700053 Publication Date 2012-05-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 11 Open Access
Notes Approved Most recent IF: 2.068; 2012 IF: 2.210
Call Number UA @ lucian @ c:irua:100310 Serial 2919
Permanent link to this record
 

 
Author Delville, R.; James, R.D.; Salman, U.; Finel, A.; Schryvers, D.
Title Transmission electron microscopy study of low-hysteresis shape memory alloys Type P1 Proceeding
Year (down) 2009 Publication Abbreviated Journal
Volume Issue Pages 02005,1-02005,7
Keywords P1 Proceeding; Electron microscopy for materials research (EMAT)
Abstract Recent findings have linked low hysteresis in shape memory alloys with phase compatibility between austenite and martensite. In order to investigate the evolution of microstructure as the phase compatibility increases and the hysteresis is reduced, transmission electron microscopy was used to study the alloy system Ti50Ni50-xPdx where the composition is systemically tuned to approach perfect compatibility. Changes in morphology, twinning density and twinning modes are reported along with special microstructures occurring when the compatibility is achieved. In addition, the interface between austenite and a single variant of martensite was studied by high-resolution and conventional electron microscopy. The atomically sharp, defect free, low energy configuration of the interface suggests that it plays an important role in the lowering of hysteresis. Finally, dynamical modeling of the martensitic transformation using the phase-field micro-elasticity model within the geometrically linear theory succeeded in reproducing the change in microstructure as the compatibility condition is satisfied. Latest results on the extension of these findings in other Ni-Ti based ternary/quaternary systems are also reported.
Address
Corporate Author Thesis
Publisher Edp Place of Publication Coutaboeuf Editor
Language Wos 000274582300009 Publication Date 2009-08-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 3 Open Access
Notes Approved Most recent IF: NA
Call Number UA @ lucian @ c:irua:81951 Serial 3716
Permanent link to this record