Heat treatment method for obtaining two-way shape memory effect of SMA (Shape Memory Alloy) material

Abstract

The invention provides a heat treatment method for obtaining the two-way shape memory effect of an SMA (Shape Memory Alloy) material. The method comprises the following steps of: stretching, bending or twisting the SMA material and keeping the shape of the stretched, bent or twisted SMA material unchanged; then heating metal on the surface layer of the SMA material by a high frequency induction heating coil and controlling a certain heating temperature and heat preservation time; and relieving the restriction at both ends of the SMA material so as to cool the SMA material under the condition of room temperature natural conversion heat exchange. The surface layer and an inner layer of the SMA material processed by the method have different crystal structures; the inner layer has low temperature in the heating process, the crystal structure of the inner layer is basically unchanged, and the inner layer shows the shape memory effect and is used as a driving material; the surface layer has high temperature in the heating process, the crystal structure of the surface layer is changed, and the surface layer shows superelasticity and is used as an elastic recovery material; the surface layer and the inner layer are matched to form the two-way shape memory effect; a prepared double-way SMA driving component has a simple structure and compact size and is very suitable for being used as a driving component in a driver.

Description

technical field [0001] The invention relates to a kind of high-frequency induction heating that can only heat the surface layer of the material, thereby heat-treating the surface layer of the SMA material, so that the surface layer is a superelastic material, and the inner layer is a material with shape memory characteristics, thereby obtaining a larger SMA material two-way memory effect of heat treatment. Background technique [0002] Shape memory alloys (Shape Memory Alloys, SMA) are widely used in engineering as drive components for drives due to their special shape memory properties and superelasticity, such as the connection and separation mechanisms used on spacecraft and the deployment mechanisms of satellite solar wings , automatic temperature control valve robot hand, etc. In many applications, SMA drive components must cooperate with biased elastic components (such as springs) to achieve two-way shape memory output. Such a design structure is more complicated and ...

AI Technical Summary

Problems solved by technology

[0004] The present invention mainly solves the problems in the two-way shape memory effect training method that the training process is complicated and time-consuming, the two-way shape memory effect is relatively limited, and the recovery strain will be further reduced as the number of cyclic actions increases. The training method of the two-way shape memory effect is simple in steps, does not need to be trained multiple times, and the two-way recovery strain after treatment is higher than that of the traditional method. The two-way SMA drive element is simple in structure and compact in size.

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