NiTi形状记忆合金的功能特性及其应用发展OA北大核心CSTPCD

As a sort of intelligent material,NiTi shape memory alloys(SMAs)are widely used in the fields of aerospace,medical devices and construction due to their functional properties such as excellent superelasticity,shape memory effect and biocompatibility.Superelasticity is characterized by a macroscopic recovery of the original shape despite large deformations,and is much larger than the recoverable elastic strain of common metals.The shape memory effect is the mutual transformation of austenite and martensite phases under temperature excitation,which is categorized into one-way,two-way and all-round shape memory effects according to the macroscopic deformation.The biocompatibility of NiTi SMAs is reflected in the low elastic modulus and low biotoxicity,which can be used in medical devices such as orthodontics,orthopedics,and cardiovascular stents.In order to fully exploit the applications of these functional properties,researchers are developing intelligent structures based on NiTi SMAs.This paper focuses on the review of the intelligent structures'applications corresponding to the different functional properties of NiTi SMAs,and introduces and discusses functional properties,problems and application fields.Meanwhile,damping and hydrogen storage properties of NiTi SMAs are explained in detail.Finally,this paper underlines the problems that need to be focused on and addressed in the applications of NiTi SMAs in various engineering fields:using additive manufacturing to tailoring the microstructure to achieve the stability improvement of superelasticity;providing theoretical guidance for the stable shape memory effect through the establishment of the intrinsic model,and further optimizing the structure to achieve the macroscopic amplification of the shape memory effect;as well as improving the corrosion resistance of NiTi SMAs in biological environments and the promotion of medical applications.Therefore,a great deal of interdisciplinary research is needed to promote the personalization and functional customization of NiTi SMAs in different applications.