Paper Title:
Effects of Annealing on Microstructure and Martensitic Transition of Ni-Mn-Co-In Ferromagnetic Shape Memory Alloys
  Abstract

The ferromagnetic shape memory alloys (FSMA) are relatively the brand new smart materials group. The most interesting issue connected with FSMA is magnetic shape memory, which gives a possibility to achieve relatively high strain (over 8%) caused by magnetic field. In this paper the effect of annealing on the microstructure and martensitic transition on Ni-Mn-Co-In ferromagnetic shape memory alloy has been studied. The alloy was prepared by melting of 99,98% pure Ni, 99,98% pure Mn, 99,98% pure Co, 99,99% pure In. The chemical composition, its homogeneity and the alloy microstructure were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The phase composition was also studied by X-ray analysis. The transformation course and characteristic temperatures were determined by the use of differential scanning calorimetry (DSC) and magnetic balance techniques. The results show that Tc of the annealed sample was found to decrease with increasing the annealing temperature. The Ms and Af increases with increasing annealing temperatures and showed best results in 1173K. The studied alloy exhibits a martensitic transformation from a L21 austenite to a martensite phase with a 7-layer (14M) and 5-layer (10M) modulated structure. The lattice constants of the L21 (a0) structure determined by TEM and X-ray analysis in this alloy were a0=0,4866. The TEM observation exhibit that the studied alloy in initial state has bigger accumulations of 10M and 14M structures as opposed from the annealed state.

  Info
Periodical
Edited by
Maria Richert
Pages
171-175
DOI
10.4028/www.scientific.net/MSF.674.171
Citation
K. Bałdys, G. Dercz, Ł. Madej, "Effects of Annealing on Microstructure and Martensitic Transition of Ni-Mn-Co-In Ferromagnetic Shape Memory Alloys", Materials Science Forum, Vol. 674, pp. 171-175, 2011
Online since
February 2011
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: Bing Tian, Dong Cai Ren, Yun Xiang Tong, Feng Chen, Li Li, Yu Feng Zheng
Symposium H: Smart Materials
Abstract:The microstructure, phase transformation and mechanical property of Ni-Co-Mn-In alloy fabricated by powder metallurgical method were studied...
222
Authors: Tadeu Castro da Silva, Daniel Monteiro Rosa, Edson Paulo da Silva
Chapter 9: Metals and Alloys in Industrial Applications
Abstract:When submitted to annealing thermal treatments Shape Memory Alloys have their phase transformation temperatures effected. The aim of the...
958