scholarly journals Oxide Formation on NiTi Surface: Influence of the Heat Treatment Time to Achieve the Shape Memory

2015 ◽  
Vol 18 (5) ◽  
pp. 1053-1061 ◽  
Author(s):  
Alana Witt Hansen ◽  
Lilian Vanessa Rossa Beltrami ◽  
Leonardo Marasca Antonini ◽  
Denis Jardim Villarinho ◽  
Julio Cesar Klein das Neves ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory ◽  
Treatment Time ◽  
Heat Treatment Time ◽  
Oxide Formation

Phase Transformations of Ferromagnetic Fe-Pd-Pt-Based Shape Memory Alloys

2003 ◽  
Vol 785 ◽  
Author(s):  
Gwon-seung Yang ◽  
Reid Jonasson ◽  
Seung-nam Baek ◽  
Kinzo Murata ◽  
Shozo Inoue ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Phase Transformations ◽  
Treatment Time ◽  
Heat Treatment Time ◽  
Induction Melting ◽  
Ferromagnetic Shape Memory Alloys ◽  
Transformation Temperatures ◽  
First Order

ABSTRACTSeveral ternary Fe-Pt-Pd alloys with the compositions of Fe-(25-x) at% Pt-x at% Pd and Fe-y at% Pt-(30-y) at% Pd were investigated to study their phase transformations in order to develop ductile ferromagnetic shape memory alloys appearing around room temperature. Alloys were prepared by vacuum floating induction melting, followed by hot rolling at 1000°C and homogenization at 900° C. Homogenized alloys were heat treated at 650°C for various periods of time in vacuum for atomic ordering in encapsulated quartz tubes, and quenched into iced water. It was found that in general the transformation temperatures changes with heat treatment time. In the case of Fe-23at.%Pt-2at.%Pd, Ms temperature increased and the difference between Ms and Mf increased with increasing heat treatment time, which was different from Fe3Pt where a degree of order becomes one. As heat treatment time increased, there was a tendency in that a strong first-order transformation in the disordered state was replaced by a weak first-order transformation. The Curie temperature of the alloys rose drastically with the addition of Pd, along with the transformation temperatures. Fe-23at.%Pt-2at.%Pd showed good shape memory effect after 8 hours of heat treatment at 650°C. This alloy showed much better shape recovery than any other binary Fe-Pt and Fe-Pd shape memory alloys.

Low-temperature thermal pretreatment process for recycling inner core of spent lithium iron phosphate batteries

2020 ◽  
pp. 0734242X2095740
Author(s):  
Haijun Bi ◽  
Huabing Zhu ◽  
Lei Zu ◽  
Yong Gao ◽  
Song Gao ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Heat Treatment Temperature ◽  
Lithium Iron Phosphate ◽  
Inner Core ◽  
Treatment Time ◽  
Iron Phosphate ◽  
Treatment Temperature ◽  
Heat Treatment Time ◽  
Physicochemical Changes

Spent lithium iron phosphate (LFP) batteries contain abundant strategic lithium resources and are thus considered attractive secondary lithium sources. However, these batteries may contaminate the environment because they contain hazardous materials. In this work, a novel process involving low-temperature heat treatment is used as an alternative pretreatment method for recycling spent LFP batteries. When the temperature reaches 300°C, the dissociation effect of the anode material gradually improves with heat treatment time. At the heat treatment time of 120 minutes, an electrode material can be dissociated. The extension of heat treatment time has a minimal effect on quality loss. The physicochemical changes in thermally treated solid cathode and anode materials are examined through scanning electron microscopy with energy-dispersive X-ray spectroscopy. The heat treatment results in the complete separation of the materials from aluminium foil without contamination. The change in heat treatment temperature has a small effect on the quality of LFP material shedding. When the heat treatment temperature reaches 300°C and the time reaches 120 minutes, heat treatment time increases, and the yield of each particle size is stable and basically unchanged. The method can be scaled up and may reduce environmental pollution due to waste LFP batteries.

Effect of Heat Treatment Condition on the Characteristics of MnO2 Added-Fe2TiO5 Ceramics for NTC Thermistors Using Local Iron Oxide

2018 ◽  
Vol 917 ◽  
pp. 64-68
Author(s):  
Wiendartun ◽  
Jaenudin Kamal ◽  
Dadi Rusdiana ◽  
Andhy Setiawan ◽  
Dani Gustaman Syarief
Keyword(s):  
Heat Treatment ◽  
Iron Oxide ◽  
Treatment Condition ◽  
Treatment Time ◽  
Heat Treatment Condition ◽  
Heat Treatment Time ◽  
Second Phase ◽  
Room Temperature Resistivity ◽  
Electrical Characteristics ◽  
Ntc Thermistor

A study on the effect of heat treatment condition on the characteristics of MnO2 added-Fe2TiO5 ceramics for NTC thermistor has been carried out. The ceramics were produced by pressing an homogenous mixture of Fe2O3 (local/ yarosite), TiO2 and MnO2 (2.0 mole %) powders in appropriate proportions to produce Fe2TiO5 based ceramics and sintering the pressed powder at 1050 °C for 3 hours in oxygen gas. Some sintered pellets were heat treated by heating them at 300 °C for 5, 15 and 25 minutes in Ar + 7% H2 gas. The XRD analyses showed that the Fe2TiO5 ceramics with and without heat treatment time had orthorhombic structure. No peak from second phase was observed from the XRD profiles. From the electrical characteristics data, it was known that the heat treatment could change the electrical characteristics of the Fe2TiO5 based-thermistor. The thermistor constant (B) and room temperature resistivity (ρRT) decreased with the increasing of heat treatment time. All ceramics made had thermistor characteristics namely B = 3459-7596 K and ρRT = 1.056-6936.062 MΩcm. Thermistor constant of the ceramics was relatively big, indicated that ceramics made from local iron oxide in this work fit the market requirement for NTC thermistor.

Effect of Heat Treatment on the Reactivity and Crystallinity of Coal-Char

2005 ◽  
Author(s):  
Shouyu Zhang ◽  
Junfu Lu ◽  
Jianmin Zhang ◽  
Qing Liu ◽  
Guangxi Yue
Keyword(s):  
Heat Treatment ◽  
Heat Treatment Temperature ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Coal Char ◽  
Heat Treatment Time ◽  
Heat Treat ◽  
Heat Treated ◽  
Layer Stacking ◽  
Crystalline Growth

The effect of heat treatment on the reactivity and crystallinity of char prepared from the vitrinite of two coals (YX, JJ) was investigated by using XRD and TGA in this paper. The results from TGA show that the reactivity of the chars from YXV and JJV decreases with the increase of heat treatment temperature. The reactivity of YXV char decreases quickly and significantly as heat treatment time increases. However, after heat treatment time of 60 min, it decreases slowly. The effect of heat treatment time on the reactivity of JJV char is small. The results from XRD show that the crystallinity of coal-char is determined by the intensity of heat treatment. When heat treatment time is more than 60 minutes, the turbostratic crystallite of YXV char prepared under 900°C changes remarkably and becomes more orderly. The aromatic layer stacking heights (Lc) of YXV Char when heat treated above 900°C increased with the increase of heat treatment time. The effect of heat treat time on Lc of JJV char is small, but under heat treatment temperature of 1200°C, the crystalline of JJV char grows distinctly. There is a good parallel relationship between the crystalline growth and deactivation of the chars. It can be concluded that the growth of the crystalline is the main reason for the deactivation of coal-char.

Sign in / Sign up

Export Citation Format

Share Document