scholarly journals Influence of holding between the thermal cycles on recovery in martensitic transformation temperatures in TiNi alloy

2019 ◽  
Vol 9 (1) ◽  
pp. 103-106
Author(s):  
Aleksei Sibirev ◽  
Sergey Belyaev ◽  
Natalia Resnina
Keyword(s):  
Martensitic Transformation ◽  
Tini Alloy ◽  
Thermal Cycles ◽  
Transformation Temperatures

Unusual Multistage Martensitic Transformation in TiNi Shape Memory Alloy after Thermal Cycling

2013 ◽  
Vol 738-739 ◽  
pp. 372-376 ◽  
Author(s):  
Aleksey Sibirev ◽  
Sergey Belyaev ◽  
Natalia Resnina
Keyword(s):  
Martensitic Transformation ◽  
Shape Memory Alloy ◽  
Thermal Cycling ◽  
Shape Memory ◽  
Temperature Interval ◽  
Defect Structure ◽  
Tini Alloy ◽  
Thermal Cycles ◽  
Unusual Phenomenon ◽  
Kinetics Of

Variation in kinetics of martensitic transformation, in an equiatomic TiNi shape memory alloy, during thermal cycles was investigated. Samples annealed at 500 °C for 1 hour were subjected to repeated thermal cycles, through the temperature range of martensitic transformation. Unusual 4-stage martensitic transformation during cooling after 30 thermal cycles was observed. Moreover, a new unusual phenomenon was found in the preliminary thermal cycled TiNi alloy. It was observed that variation in the highest temperature Th of thermal cycles temperature interval resulted in the redistribution of released heat among four calorimetric peaks, observed on cooling. It was found that if the Th temperature did not exceed 240 °C the variation in kinetics was repeatable, and determined only by the value of Th. It was assumed that the defect structure induced on preliminary thermal cycling changes reversibly on cooling and heating.

Martensitic transformation in TiNi alloy at loading

2001 ◽  
Author(s):  
Sergey A. Egorov ◽  
Margarita E. Evard
Keyword(s):  
Martensitic Transformation ◽  
Tini Alloy

scholarly journals Interrelation of microstructure and thermodynamic parameters in TiNi alloy during multiple martensitic transformations

2019 ◽  
Vol 298 ◽  
pp. 00002
Author(s):  
Anna Churakova
Keyword(s):  
Thermodynamic Parameters ◽  
Rapid Heating ◽  
Martensitic Transformations ◽  
Coarse Grained ◽  
Tini Alloy ◽  
Thermal Cycles ◽  
Fast Heating ◽  
Heating And Cooling ◽  
Coarse Grained State ◽  
Consistent Increase

The effect of multiple martensitic transformations on the microstructure and thermodynamic parameters of the alloy of the TiNi system was investigated. It was shown that in the Ti50Ni50 alloy, with an increase in the number of thermal cycles with rapid heating and cooling up to n = 100, a consistent increase in the dislocation density occurs, and a decrease in the width of martensitic plates is observed. And also, that in TCs with fast heating and cooling of the Ti50Ni50 alloy in a coarse-grained state, a change in the trend in the temperatures of martensitic transformations is observed — with an increase in the number of thermal cycles to n = 50, they decrease, and at n> 50 the temperatures increase.

Investigation of Ageing Phenomena in CuAlNi Based Shape Memory Alloys

2007 ◽  
Vol 537-538 ◽  
pp. 129-136 ◽  
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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