Fatigue Life of Ti-Ni-Cu Shape Memory Alloy under Thermo-mechanical Cyclic Conditions.

俊雄, 佐久間; 宇一, 岩田; 啓, 高久; 房亮, 仮屋; 保雄, 越智; 隆, 松村

doi:10.1299/kikaia.66.748

Cited by 11 publications

(8 citation statements)

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“…The response of SMA actuators is dependent on its temperature, and the generative force of them is determined by the recovery stress of SMAs, that is, the higher recovery stress leads to the higher driving force and smaller hysteresis leads to the higher response of driving. Also in the SMAs, Ti-Ni-Cu alloys are one of promising materials for a component of SMA actuators, because the recovery stress increases and the stress hysteresis and transformation temperature hysteresis decrease with increasing copper content in the alloys [7][8][9] . …”

Section: Introductionmentioning

confidence: 99%

Effect of Aging Treatment on Transformation Temperature Difference and Temperature Hystelisis of Ti-Ni-Cu Shape Memory Alloy after Pre-Deforming

Cho

Mutoh

Takeda³

et al. 2010

Trans. Mat. Res. Soc. Japan

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In order to improve the performance of actuator using shape memory alloy, we studied the effects of aging-treatment on transformation temperature difference and temperature hysteresis of Ti-Ni-Cu shape memory alloy. The chemical composition of specimen is Ti-41.7Ni-8.5Cu (at%) and cold working ratio (CW) is 10% and 40%. Aging temperature is 673K, and aging time is varied from 3.6ks to 1800ks. In the case of CW=10%, the transformation temperatures have a little dependence on aging time. However, in the case of CW=40%, A s and M f increase with increasing of aging time. This difference is caused by the variation of dislocation density by aging and the difference of sensitivity to dislocation density of each transformation temperature. Moreover, the temperature response (A f -A s ) of CW=40% increases with increasing aging time.

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Section: Introductionmentioning

confidence: 99%

Effect of Aging Treatment on Transformation Temperature Difference and Temperature Hystelisis of Ti-Ni-Cu Shape Memory Alloy after Pre-Deforming

Cho

Mutoh

Takeda³

et al. 2010

Trans. Mat. Res. Soc. Japan

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“…In areas such as engineering and medicine, its applications are being studied and practically used [1][2][3]. As an example of an application, a reciprocating-type heat engine that incorporates a Ti-Ni shape memory alloy wire has been proposed [4,5]. This heat engine is a system that converts heat energy into mechanical energy by using the shape recovery function due to reverse transformation, and collects low-temperature heat energy that has not been used because of the low latent heat source, which is within the temperature range for martensite transformation and reverse transformation of the alloy.…”

Section: Introductionmentioning

confidence: 99%

Probabilistic Estimation of the Degradation of Function and Strength of Ti-41.7Ni-8.5Cu (at%) Shape Memory Alloys under Thermo-Mechanical Cyclic Conditions

Hosogi

Okabe

Sakuma

et al. 2003

Journal of the Society of Materials Science, Japan

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Machines and systems that use shape memory alloys require the optimum design for combining functional properties and structural strength. In the reliability study of functional and structural design, the scatter as well as the behaviors of the functional and mechanical properties of the alloys during practical use should be considered. In this study, considering the application of Ti-41.7 Ni-8.5Cu (at%) to a reciprocating-type heat engine, the increase of the irrecoverable strain with increasing number of thermo-mechanical cycles was clarified experimentally and the irrecoverable strain was used as a parameter for predicting the behaviors of functional and structural properties. Thus, models of the behaviors of irrecoverable strain were made to estimate functional properties such as transformation points and recovery stress as a function of irrecoverable strain. To analyze the scatter of irrecoverable strain, the ratio of experimental data to the value estimated from the model was considered and found to show the Weibull distribution. The probabilistic expression estimated as an inverse function of cumulative probability P was proposed to predict probabilistically the recovery energy and the dispersion energy by using irrecoverable strain sir, as an estimation parameter. The proposed model for the behavior of the functional degradation and fatigue strength properties of Ti-41.7% Ni-8.5% Cu shape memory alloys under thermo-mechanical cyclic conditions can be used for the optimum design that combines the functional properties and structural strength of machines and systems such as a reciprocating-type heat engine that uses shape memory alloys.

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“…As applicable alloys, the Ti-Ni-Cu system shape memory alloys are superior to other alloys such as the Ti-Ni system and the Cu system, and have been continuously developed as elements for energy conversion, because of their superior fatigue properties and corrosion resistance. From the viewpoint of thermal engine development, we have noted that the mechanical and functional properties of cyclic deformation behavior may be improved by adding copper to the Ti-Ni binary alloy, because the recovery stress increases with increasing Cu content, and both stress hysteresis and transformation strain decrease with increasing Cu content [4,5]. Furthermore, copper addition is effective for decreasing temperature hysteresis.…”

Section: Introductionmentioning

confidence: 99%

Effects of Cold Working and Heat Treatment on Transformation Temperature of Ti-41.7Ni-8.5Cu (at%) Shape Memory Alloy and Its Probabilistic Prediction

Hosogi

Okabe

Sakuma

et al. 2003

Journal of the Society of Materials Science, Japan

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Abstract:The transformation temperatures of shape memory alloy vary with the composition and processing and manufacturing conditions of the alloy. The purpose of the present study is to clarify the effects of cold working and heat treatment on various transformation temperatures, and to estimate probabilistically the transformation temperatures by means of a model. The shape memory alloy used was Ti-41.7Ni-8.5Cu (at%), and the transformation temperatures were measured by the differential scanning calorimeter method (DSC method). The effects of processing and heat treatment on the transformation temperatures were investigated by changing the cold working ratio (10-40%) and the heat treatment temperature (623-773K), respectively. As a result, the transformation temperatures were found to decrease with increasing cold working ratio. The transformation temperatures were also found to increase with increasing heat treatment temperature. Therefore, the transformation temperatures were modeled by considering quantitatively the effects of the cold working ratio and the heat treatment temperature. A probabilistic prediction formula was proposed so that the reliability of the prediction may be estimated quantitatively.

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Fatigue Life of Ti-Ni-Cu Shape Memory Alloy under Thermo-mechanical Cyclic Conditions.

Cited by 11 publications

References 0 publications

Effect of Aging Treatment on Transformation Temperature Difference and Temperature Hystelisis of Ti-Ni-Cu Shape Memory Alloy after Pre-Deforming

Effect of Aging Treatment on Transformation Temperature Difference and Temperature Hystelisis of Ti-Ni-Cu Shape Memory Alloy after Pre-Deforming

Probabilistic Estimation of the Degradation of Function and Strength of Ti-41.7Ni-8.5Cu (at%) Shape Memory Alloys under Thermo-Mechanical Cyclic Conditions

Effects of Cold Working and Heat Treatment on Transformation Temperature of Ti-41.7Ni-8.5Cu (at%) Shape Memory Alloy and Its Probabilistic Prediction

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