Memory alloy phase-change temperature measuring method and measuring system for implementing same

Abstract

The invention discloses a memory alloy phase-change temperature measuring method. The measuring method comprises the following steps: firstly measuring a sound velocity-temperature curve in which the velocity of ultrasonic longitudinal waves in a memory alloy to be measured changes along with the temperature, wherein the sound velocity-temperature curve comprises a heating curve and a cooling curve; and determining the phase-change temperature of the memory alloy to be measured according to the sound velocity-temperature curve by using the sensitivity of the ultrasonic longitudinal velocity on the phase-change process of the memory alloy. The invention also discloses a measuring system implementing the measuring method. The measuring system comprises an ultrasonic wave emitting and receiving module, a signal collecting and analog-to-digital converting module, a sample temperature adjusting module and a control and data processing module. According to the measuring method and the measuring system, the phase-change temperature of the memory alloy is measured by using the sensitivity of the ultrasonic longitudinal wave velocity on the phase-change process of the memory alloy; compared with the prior art, the measuring method and the measuring system have the advantages of high sensitivity, strong reliability, wide application range and nondestructive measurement.

Description

technical field [0001] The invention relates to a measurement technology for the phase transition temperature of an intelligent material structure, in particular to an ultrasonic-based method for measuring the phase transition temperature of a memory alloy and a measurement system for realizing the measurement method. Background technique [0002] Shape memory alloys (Shape Memory Alloy, SMA), or memory alloys for short, are new materials that are increasingly used in engineering, biomedicine, and micro-electromechanical fields. They are also used in smart structures as excellent sensitive components and drivers. The shape memory effect and superelasticity it presents are caused by the thermoelastic martensitic phase transition, which has a great influence on the thermodynamic behavior of SMA. Accurate and effective measurement of phase transition temperature is of great significance to the development and application of SMA. At present, the measurement methods of phase tran...

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Problems solved by technology

[0005] When the acoustic emission method is used for phase change detection, there are noises and interference from other AE sources, which have a great impact on the phase change temperature obtained by analyzing the phase change AE signal. There are also higher requirements

Therefore, although acoustic emission is a promising test method with high measurement accuracy, it is not widely used in industry at present.

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