OS0913 Effect of Alloy composition on phase transformation temperature of Zr-Cu system shape memory alloy

The effect of annealing temperature（300-600°C）on the microstructure and transformation temperature of NiTiNb shape memory alloy rods deformed with equal channel angular pressing（ECAP） method was analyzed. The results show that the hard brittle phase （Ti,Nb）2Ni was decreased after ECAP. With the rising of annealing temperature, the number of β-Nb phase increase while eutectic declines. The DSC analysis shows that the martensite and reverse transformation temperature increase with annealing temperature. After annealing with 500°C, the martensite/austenite transformation starting temperatures rise to -64.6°C and -30.1°C, respectively.

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Determination of Transformation Temperatures of SMAs by Varying the Force Using Dead Weight Method

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.813-814.166 ◽

2015 ◽

Vol 813-814 ◽

pp. 166-171

Author(s):

Kiran D. Jadhav ◽

U.S. Mallikarjun ◽

S.H. Adarsh ◽

S. Prashantha

Keyword(s):

Phase Transformation ◽

Shape Memory ◽

Transformation Temperature ◽

Phase Transformation Temperature ◽

Scanning Calorimetry ◽

Dead Weight ◽

Strain Behavior ◽

Weight Method ◽

Nitinol Alloy ◽

Dsc Method

Shape-memory material is an alloy that “Remembers” its original shape and that when deformed to its Pre-deformed shape when heated. Phase transformation temperature is one of the most important parameters for the shape memory alloys. In this present work phase transformation temperature is measured by the dead weight method and compared with standard Differential scanning calorimetry (DSC) method. The objective of this paper is to study the microstructure of the Shape memory alloy (SMA) wire, determining the Phase Transformation temperature of NiTinol alloy i.e. Marteniste start (Ms), Martensite finish (Mf), Austenite Start (As), Austenite finish (Af) by a Dead Weight method and also studying the stress-strain behavior with variation of Temperatures to show the Shape memory effect in the NiTinol SMA wire.

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High-Temperature Shape Memory Alloys Based on Ti-Platinum Group Metals Compounds

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.2541 ◽

2014 ◽

Vol 783-786 ◽

pp. 2541-2545 ◽

Cited By ~ 10

Author(s):

Yoko Yamabe-Mitarai ◽

Abdul Wadood ◽

Raju Arockiakumar ◽

Toru Hara ◽

Madoka Takahashi ◽

...

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Phase Equilibria ◽

Shape Memory Alloys ◽

Shape Memory ◽

Transformation Temperature ◽

Shape Recovery ◽

Platinum Group Metals ◽

Phase Transformation Temperature ◽

Temperature Phase

The effect of alloying to TiPd and TiPt on phase transformation temperature, phase equilibria, and shape recovery were investigated for TiPt and TiPd base high-temperature shape memory alloys. Ru, Ir, Co and Zr were chosen for additional elements and Zr was found as the most effective element to improve shape recovery of TiPd and TiPt.

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Effect of the Cooling Time in Annealing at 350°C on the Phase Transformation Temperatures of a Ni55Ti45 wt. Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1120-1121.958 ◽

2015 ◽

Vol 1120-1121 ◽

pp. 958-961

Author(s):

Tadeu Castro da Silva ◽

Daniel Monteiro Rosa ◽

Edson Paulo da Silva

Keyword(s):

Differential Scanning Calorimetry ◽

Phase Transformation ◽

Shape Memory Alloy ◽

Shape Memory ◽

Cooling Time ◽

Phase Transformation Temperature ◽

Thermal Treatments ◽

Heating Rates ◽

Scanning Calorimetry ◽

Transformation Temperatures

When submitted to annealing thermal treatments Shape Memory Alloys have their phase transformation temperatures effected. The aim of the present work is to investigate the effects of cooling time in the phase transformation temperatures of Ni55Ti45in w.t. % alloy annealed at 350°C. Samples of this alloy were maintained at 350°C for one hour and then cooled in the same furnace for 10 minutes, 1 hour and 24 hours. The phase transformation temperatures were measured by means of Differential Scanning Calorimetry (DSC) at cooling and heating rates of 20°C/min. The results show that the annealing at 350°C changed the phase transformation up to 54%. For 10 minutes cooling time the Mftemperature increase from 15,65°C to 24,1°C. For the others cooling times the phase transformation temperature did not change significantly. Therefore, the cooling time for the annealing at 350°C did not effect the phase transformation temperatures of the Ni45Ti55in wt % shape memory alloy.

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