Effect of Nb Content on Martensitic Transformation Temperatures and Mechanical Properties of Ti-Ni-Nb Shape Memory Alloys for Pipe Joint Applications

Effect of isothermal aging on martensitic transformation temperatures, mechanical properties and microstructure was investigated for a Ni-rich Ti-Zr-Ni shape memory alloy at temperatures ranging from 673 K to 773 K. The aging behaviour was two stage process: the first stage associated with an increase in the Vickers hardness and a decrease in martensitic transformation temperatures and the second stage with a decrease in the hardness and increase in the transformation temperatures. Second stage was also characterized by the appearance of nano-scale precipitates, which has never been reported.

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Martensitic transformation and mechanical properties in Ni–Co–Mn–In–Gd metamagnetic shape memory alloys

Materials Science and Engineering A ◽

10.1016/j.msea.2018.04.030 ◽

2018 ◽

Vol 725 ◽

pp. 359-363 ◽

Cited By ~ 3

Author(s):

Hang Li ◽

Xianglong Meng ◽

Wei Cai

Keyword(s):

Mechanical Properties ◽

Martensitic Transformation ◽

Shape Memory Alloys ◽

Shape Memory

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Effect of Nitrogen Addition on TiNi Shape Memory Alloys

Science of Advanced Materials ◽

10.1166/sam.2020.3806 ◽

2020 ◽

Vol 12 (9) ◽

pp. 1403-1408

Author(s):

Izaz Ur Rehman ◽

Tae-Hyun Nam

Keyword(s):

Mechanical Properties ◽

Shape Memory Alloys ◽

Shape Memory ◽

Tensile Tests ◽

Nitrogen Addition ◽

Ternary Alloys ◽

X Ray Diffraction ◽

Transformation Temperatures ◽

Arc Melting ◽

Type Phase

In present paper we will show how nitrogen effects microstructures, transformation temperatures, and mechanical properties of equiatomic Ti50–Ni50 and Ti-rich Ti51–Ni49 binary shape memory alloys. 0.5 at.% of nitrogen was added to prepare Ti50–Ni49.5–N0.5, and Ti51–Ni48.5–N0.5 (at.%) alloys by arc-melting. Microstructures were investigated by scanning electron microscope (SEM), phase constitutions were investigated by X-ray diffraction (XRD), transformation temperatures were investigated by differential scanning calorimeter (DSC) and mechanical properties were tested by tensile tests. Solutions treated Ti–Ni–N shape memory alloys contain TiNi matrix without nitrogen, Ti2Ni type phase containing a small amount of nitrogen and a new Ti2N type phase containing a small amount of nickel. Compared with Ti50–Ni50 and Ti51–Ni49 binary alloys, the martensitic transformation starts temperatures (Ms) of Ti50–Ni49.5–N0.5 and Ti51–Ni48.5–N0.5 ternary alloys decreased from 63.4 °C to 41.6 °C and from 85.3 °C to 79.4 °C, respectively. By adding N, fracture strain decreased and incomplete superelasticity was observed.

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Effect of Nb-Content on Mechanical Properties of (Ni47Ti44)100-xNbx Shape Memory Alloys

Materials Science Forum - PRICM-5 ◽

10.4028/0-87849-960-1.1945 ◽

2005 ◽

pp. 1945-1948

Author(s):

Xiang Ming He ◽

De Sheng Yan ◽

Zhi Min Jiang ◽

Li Jian Rong

Keyword(s):

Mechanical Properties ◽

Shape Memory Alloys ◽

Shape Memory ◽

Nb Content

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Microstructure and martensitic transformation and mechanical properties of cast Ni rich NiTiCo shape memory alloys

Materials Science and Technology ◽

10.1179/1743284713y.0000000478 ◽

2014 ◽

Vol 30 (14) ◽

pp. 1795-1800 ◽

Cited By ~ 11

Author(s):

N. El-Bagoury

Keyword(s):

Mechanical Properties ◽

Martensitic Transformation ◽

Shape Memory Alloys ◽

Shape Memory

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Investigation of Ageing Phenomena in CuAlNi Based Shape Memory Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.537-538.129 ◽

2007 ◽

Vol 537-538 ◽

pp. 129-136 ◽

Cited By ~ 1

Author(s):

Marton Benke ◽

Valéria Mertinger ◽

E. Nagy ◽

Jan Van Humbeeck

Keyword(s):

Martensitic Transformation ◽

Shape Memory Alloys ◽

Shape Memory ◽

Ternary Alloy ◽

Room Temperature ◽

Beta Phase ◽

Heat Treatments ◽

Thermoelastic Martensitic Transformation ◽

Transformation Temperatures ◽

Exothermic Process

The ageing phenomena and its effect on the thermoelastic martensitic transformation was investigated in three Cu-base SMAs. The transformation temperatures shifted to higher temperatures due to aging in the beta-phase. To increase the alloy’s ductility, a definite amount of Mn (4 wt%) and Fe (2 wt%) were added to the ternary alloy. The thermoelastic martensitic transformation was found in the not-aged samples of the CuAlNiMn and CuAlNiMnFe alloys. This transformation was destroyed due to ageing heat treatments by a fairly unknown exothermic process. The thermoelastic martensitic transformation appeared again in the aged CuAlNiMn and CuAlNiMnFe samples after keeping them on room temperature for a few months. This phenomena was investigated by DSC, SEM, TEM, and XRD.

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