Properties of TiNi shape memory alloy and its application in textile
Zhang Dan, Xu Lei, Wang Rui Abstract: The shape memory effect, superelasticity, wear resistance and fatigue properties of TiNi shape memory alloys are reviewed. The application status of TiNi shape memory alloys in textiles is discussed, and its research direction and prospects in textiles are prospected. Carton Opener Cutter Knife,Snap off Cutter Knife,18mm Cutter Knife Shangqiu Acer Measuring Tool Co.,Ltd. , https://www.acertoolshn.com
(College of Textile Science, Tianjin Polytechnic University, Tianjin 300160, China)
Key words: TiNi; shape memory alloy; superelasticity; wear resistance; fatigue performance; application CLC number: TS190·1 Document code: AArticle ID:1673-0356(2011)03-0036-03
Shape memory alloy (SMA) refers to a kind of alloy with a certain shape, which is plastically deformed at a low temperature and fixed into another shape. When it is heated to a certain critical temperature, it can be restored to the initial state. shape. The function of the alloy to restore its original shape is called the shape memory effect (SME) [1].
Shape memory alloys mainly include copper-based shape memory alloys (CuZn, CuZnAl, CuAlNi, etc.), iron-based shape memory alloys (FePt, FePd, FeMnSi, etc.) and TiNi alloys. The most common of these research and applications are TiNi alloys. TiNi alloys are currently the fastest growing in the United States, followed by Japan and Europe [2].
As a new type of functional material, TiNi alloy has the most outstanding performance because of its shape memory effect, due to its stable shape memory and superelastic function, as well as excellent processability, strength, wear resistance, corrosion resistance and Biocompatibility and other properties, its application prospects are limitless. Applying it to textiles can give the fabric a special dynamic and change, which gives people a greater visual impact on the appearance, while its excellent performance can give the textile more functionality and comfort. This paper reviews the performance of TiNi shape memory alloy wire at home and abroad and its research and application status in textiles, and points out the problems that need to be solved for the further application of TiNi shape memory alloy wire in textile.
1 Properties of TiNi shape memory alloys 1·1 Shape memory effect Ordinary metal materials first undergo elastic deformation after being subjected to external force. When the yield point is reached, plastic deformation occurs, and after the stress disappears, permanent deformation is left. When the TiNi shape memory alloy is plastically deformed at normal temperature, if the temperature can return to above its phase transition temperature, it can return to the shape before deformation due to its characteristic shape memory effect.
The shape memory effect produces conditional martensite (M) phase transition is thermoelastic, the mother phase and M phase are ordered lattice structure, M is internal twin deformation, and the phase transition is completely reversible in crystallography. The M phase of the TiNi alloy has a small thermal hysteresis and a small phase change driving force [3]. In the phase change process, when M is formed, the elastic deformation at the interface increases as the M piece grows. At a certain temperature, when the phase transformation elastic deformation energy and the coherent interface energy increase to the same as the phase change driving force, the new phase and the parent phase reach the thermoelastic equilibrium state, and the phase transition stops. At this time, the deformation does not exceed the elastic limit of the material. If the temperature continues to decrease, the driving force increases due to the M phase change, and M continues to grow. When the temperature rises and the phase change driving force decreases, since the interface between M and the mother phase is not broken and maintains elastic contact, the M piece shrinks as the temperature rises. An alloy having a thermoelastic M phase transition, the mother phase having a highly symmetrical crystal structure, and M being a low symmetry structure (diamond, orthogonal, monoclinic), and when the mother phase is cooled, a multi-variant M is formed, which Under the action of external force, the M exhibits a stress-preferred orientation and tends to a single variant. The material exhibits deformation, which is called self-collision. However, M is a single variant after deformation. When the reverse phase transformation is performed, the symmetry of M is low, and the number of variants is small, which will return to the state of the mother phase of the ordered structure, and the shape of the alloy recovers, showing SME [4]. The SME of Ti-Ni alloy is divided into one-way, two-way and full-range memory effects.
1·2 Superelastic Super elastic refers to the phenomenon that the specimen produces a strain far greater than its elastic limit strain under the action of external force, and the strain can be automatically recovered during unloading.
There are two conditions for the generation of superelasticity. One is that the yield strength of the parent phase is high to delay the plastic deformation; the other is that the deformation temperature is above Af, so that the stress induces M to undergo reverse phase transformation after unloading. In essence, shape memory alloys have different superelastic and shape memory effects, and the mechanism is similar. The only difference is that superelasticity is caused by M reverse phase transformation after stress is released to return the shape to the mother phase state, and shape memory effect is heated. The reverse phase transition is returned to the parent phase [5].
1·3 Wear resistance The results of cavitation, water jet wear, sandblasting wear, dry friction wear, corrosion wear and abrasive wear of TiNi alloy show that the wear performance of TiNi alloy is better than that of traditional wear resistant material, which is friction and wear. Good selection of components [6]. Li Zhenhua et al. [7] showed that the microstructure of the alloy was refined, and when the second phase of the dispersed and fine Ti3Ni4 precipitated, the recoverable strain rate increased from 40% to 63%, and the friction performance was improved. The friction coefficient was from 0. · 141 dropped to around 0. 06, and the amount of wear was also significantly reduced.
1·4 Fatigue properties TiNi shape memory alloys have good fatigue, corrosion and wear resistance. In the process of wear, the mutual coordination and superelasticity of martensite variants are the main reason for the wear resistance of TiNi alloys [8-9]. Due to the superelastic effect caused by stress-induced martensite transformation, the parent phase changes to induce martensite under the action of external force; after the external force is removed, the stress-induced martensite is reversely transformed into the parent phase. This phase structure change can effectively consume external force and reduce the damage of the external force on the surface of the TiNi shape memory alloy. At the same time, the TiNi alloy undergoes martensite reorientation under the action of external force, which can eliminate part of the strain, making it difficult to form slip and dislocation in the microstructure, and reducing the degree of wear of martensite [10].
G. Eggeler et al. [11] studied three different fatigue states of TiNi alloy, including: 1 fatigue stress-strain hysteresis of superelastic TiNi alloy wire under low cyclic tension; 2 stress induced martensite phase The local strain produced by the change; 3 the functional fatigue of the general TiNi alloy spring. It is also verified that the microstructure of the TiNi alloy determines the fatigue stress-strain response stability caused by the periodic load and determines the occurrence of strain and phase transition.
2. Application Status of TiNi Shape Memory Alloy in Textiles 2.1 Status of Foreign Application Research (1) Italian company, using shape memory alloy fiber to manufacture intelligent shirts, using titanium-nickel memory alloy fiber and nylon blending, proportion Five nylon wires were used for one nylon wire. When the ambient temperature of the smart shirt rises, the sleeve of the shirt will automatically roll up immediately. And the shirt is not afraid of wrinkles, even if it is a mess, blow it with a hair dryer, it will be able to recover immediately, and even the body temperature can automatically "smooth" it [12].
(2) Japan has developed a curtain that can control its light transmission by weaving a shape memory wire. If the temperature in the room is below a certain value, the fabric will automatically close, it acts like an insulator to maintain the temperature inside the room. Conversely, if the temperature in the room is above a certain value, the fabric with the shape memory structure is automatically opened, allowing the air to flow freely for cooling. Therefore, the shape memory fabric can be used as the blinds. This specially designed fabric with shape memory is very sensitive to the sun. The daylight blinds can automatically adjust the amount of sunlight entering, and the blinds at night are automatically closed. It can control the comfort temperature of the room as well as the influence of strong sunlight on human vision [13].
(3) The United Kingdom has developed an anti-scald garment, which is made of nickel-titanium alloy fiber into a pagoda-type spiral spring shape, which is then processed into a flat shape and fixed in the fabric. When the surface of the garment is exposed to high temperature, the shape memory effect of the fiber is induced, and the fiber is rapidly converted from a plane to a pagoda shape, so that a large gap is formed between the two layers of fabric, and the human skin is separated from the high temperature to prevent burns. A fabric in which a shape memory wire is added to such a sandwich to create a void, which imparts excellent heat insulation, also provides warmth for clothing worn in an extreme environment [14-15].
(4) Cha et al. of the Textile Institute of the University of Herior-Watt in Scotland, on the Gemmel and Dunsmone fancy spinning machine, fed the wire yarn from a set of drafting rollers into the machine as a core yarn. Wrapped. By changing the computer program, controlling the position of the yarn in the roller, a wide variety of fancy lines [16] are produced and the fabric is woven.
2·2 Status of domestic application research (1) Patent of alloy wire for bra. The publication No. CN1422563 "a shape-protecting health bra lining, bra and underwear" [17] uses a memory alloy wire mesh and a closed mouth to form a bra lining. The memory alloy wire mesh has good air permeability and strong shape retention ability. The edge of the wire head and the memory alloy wire mesh is covered by the mouth to avoid the stimulation of the skin of the memory alloy wire and the memory alloy wire mesh, and the shape of the shape memory alloy can further enhance the shape retention ability of the liner. . The patent of CN 2378955, "A Bra with Shape Memory Capability" [18], is characterized in that the inner liner comprises a TiNi shape memory alloy or other superelastic alloy wire mesh coated with a plurality of venting holes. The lining can be made of a variety of textiles, non-woven fabrics, leather as a mask to make a bra or underwear with such a bra. There is also a patented "grid-like memory alloy super-elastic bra cup" [19] and "smart body bra" [20].
(2) Patent of alloy wire for lining. Patent No. CN2419851, "A lining with shape memory ability" [21], is a shape memory alloy monofilament, sheet or filament as a carrier for a shoe or the like or a part thereof or coated with silicone. The alloy wire mesh or other structure forms a silicone-coated alloy wire mesh lining, which enables the original shape of the carrier such as the shoe and hat to be maintained for a long time, and is beautiful and durable. The inner lining can be placed on a carrier such as a shoe, a cap, a bag or the like or a part thereof as a lining, and a shoe, a cap, a clothing shoulder pad, and the like which are made of various fabrics, non-woven fabrics, and leather. Patent No. CN2443628, "Sports shoes using shape memory alloys" [22], uses a shape memory alloy in which a high elasticity is embedded in the upper. The sneaker is provided with a front upper, a back upper, a side upper, a rear upper and a padded belt, wherein a shape memory alloy made of a highly elastic material is at least embedded in one part of the sports shoe to prevent external impact. Distorted with the foot. In addition, the smart baby developed by Nitinol Technology Co., Ltd. in Beijing can be changed in thickness according to changes in external temperature.
3. Conclusion TiNi shape alloy wire As a new type of textile material, the application of TiNi shape memory alloy wire in textile is still in its infancy due to its excellent performance and the unique performance advantages of the products produced by combining with textiles. Therefore, its deeper application is also subject to some conditions: (1) TiNi alloy wire should be used as a textile material. At present, the wire can be drawn to the finest diameter of about 0.3 mm. How to optimize the process A finer and more uniform alloy wire for better application is a major problem to be solved in the future. (2) Due to the finer diameter of TiNi alloy wire, the shape memory effect is reduced, and the shape memory effect is the most important performance of the new material. How to make better use of TiNi alloy without affecting its shape memory effect Silk is also a subject that needs to be studied in depth.
references:
[1]鄢飞,é²åŒæŸ±.Characteristics and application of TiNi shape memory alloy[J].Neurological Damage and Functional Reconstruction,2007,(2):371.
[2] Hu Jinlian. Shape Memory Textile Materials [M]. Beijing: China Textile Press, 2006.
[3]WANG Yongshan, HE Zhirong, WANG Qi, et al. Research progress in properties and applications of Ti-Ni shape memory alloys[J]. Potential Processing Technology, 2009, (20): 24-27.
[4] Zhao Liancheng, Cai Wei, Zheng Yufeng. Shape memory effect and superelasticity of alloys [M]. Beijing: National Defence Industry Press, 2002: 5-28.
[5]LI Guangbo, CUI Di, HONG Shumeng.Experimental study on mechanical properties of superelastic shape memory alloy wire[J].Journal of Dalian University,2008,29(3):129-133.
[6]XU Renbo, CUI Lishan. Progress in Erosion Wear Behavior and Application of TiNi Alloy[J].Materials Review,2008,22(5):55-57.
[7]LI Zhenhua, CHENG Xianhua. Tribological properties of TiNi alloy prepared by equal-diameter bending method[J]. Journal of Shanghai Jiaotong University, 2008, 42(1): 57-60.
[8]Takashi Fukuda, Mokoto Takahata, et al. Two Way Shape Memory
Properties of Ti-51Ni Single Crystal IncludingTi3Ni4Precipitate of a
Single Variant [J]. MaterialsTransactions, 2001,42(2):21.
[9]LIU Wei,ZHENG Yu-gui,RAO Guang-bin, et al.Effect of phase transition pseudoelasticity on multiphase flow damage of TiNi alloy[J]. 金属å¦æŠ¥,2002,42(2): 185-188.
[10] Li Qiquan, Qi Shan, Wang Shidong. Research Status of Superelasticity of TiNi Shape Memory Alloys[J].Shanghai Nonferrous Metals,2003,(4):170-174.
[11]G Eggeler. Structural and functional fatigue of Ni-Tishape memory
Alloys[J]. Materials Science and Engineer-ing, 2004A, 378:24-33.
[12]Rachael CC Winchester, George K Stylios.Designingknit-ted apparel
By engineering the attributes of shapememoryalloy[J].International
Journal of Clothing Science & Technology, 2003, 15 (5): 359-362.
[13] Liu Xiaoxia, Hu Jinlian. Research progress of shape memory alloy in textile industry[J]. Journal of Textile Research, 2005, (6): 26.
[14] Liu Yan, Hu Jinlian. Preparation and Development Prospect of Shape Memory Textiles[J]. Progress in Textile Science and Technology, 2005, (5): 7-9.
[15] Li Yanfeng, Mi Xujun, Gao Baodong, et al. Research status of fatigue behavior of TiNi-based shape memory alloy. Material Herald, 2007, (6).
[16]C Invernizzi, P Iora, heat recovery from a micro-gas tur-bine by
Vapor jet refrigeration systems[J].Applied Ther-mal Engineering,2005
(25): 1233-1246.
[17] Zhou Xing. A conformal health bra lining, bra and underwear, CN1422563[P].
[18] Zhou Xing, Zhu Ming, Wang Siquan, et al. A bra with shape memory ability, CN2378955[P].
[19] Yang Heng, Wang Lanying, Yin Shengning, et al. Grid-like memory alloy super elastic bra cup, CN2446788[P].
[20] Du Yanliang. Intelligent bodybuilding bra, CN2337786[P].
[21] Zhou Xing, Zhu Ming, Wang Siquan, et al. A lining with shape memory ability, CN2419851[P].
[22]金星é•. Sports shoes using shape memory alloy. CN2443628.[P]