How the initial shape of a shape memory alloy is made

When the critical temperature is reached, the initial shape can be changed.

It can be imagined by a three-dimensional stereoscopic image.

Through crystal conversion.

Make some changes.

Let everyone feel that if we use the bone plate for bone grafting, it can also be generated by memory alloy, that is, the compressive force is generated in the process of restoring the original shape. The discovery that allows our own broken bones to be combined is indeed a great convenience for some of our human life and work.

It is mainly converted through crystals, which convert diamond-shaped crystals into simple three-dimensional structures, so that these objects are deformed.

It is made by using different alloy components, and it contains many new materials, so it is relatively unique.

It should be heated before quenching. At the same time, the shape should be fixed during the heating process. It can also be fixed on the mold. The shape on the mold is then maintained during heating. Finally, it is quenched in cold water, and it is ready.

1. Features: It has a shape memory effect, taking the spring made of memory alloy as an example, put this spring in hot water, the length of the spring will be extended immediately, and then put it in cold water, it will immediately return to its original state;

It has pseudoelasticity, which is manifested in the fact that under the action of external forces, the shape memory alloy has a much greater deformation recovery ability than ordinary metals, that is, the large strain generated during loading will recover with unloading.

2. Uses: aviation and space devices. For example, the low-temperature fitting connector used in the hydraulic system of military aircraft, Europe and the United States are developing shape memory alloy materials for intelligent horizontal rotors of helicopters.

It can also meet the requirements of chemistry and biology, i.e. good biocompatibility.

Categories: Education Science >> Science & Technology >> Engineering Technology Science.

Problem description: Anyone who works in a mechanical-related enterprise or knows more about it will introduce me to the application of shape memory alloy in mechanical systems, and it is best to introduce some relevant information, books are also OK.

Analysis: Early applications were pipe fittings, but also for temperature control devices (e.g., temperature control traps), integrated circuit leads, automotive parts, and so on.

Industrial applications: 1) One-way shape recovery using the one-way shape memory effect. Such as pipe joints, antennas, collars, etc.

2) Extrinsic bidirectional memory recovery. That is, the one-way shape memory effect is used and the external force is used to make repeated actions with the rise and fall of temperature, such as thermal components, robots, binding posts, etc.

3) Intrinsic bidirectional memory retrieval. That is, the two-way memory effect is used to make repeated actions with the rise and fall of temperature, such as bright heat engines, thermal elements, etc. However, this type of application has fast memory decay and poor reliability, so it is not commonly used.

4) Hyperelastic applications. Such as springs, binding posts, glasses frames, etc.

Medical applications: The biocompatibility of the tini alloy is very good, and there are quite a few medical examples of using its shape memory effect and superelasticity. Such as thrombus filters, spinal orthopedic rods, dental orthopedic wires, cerebral aneurysm clips, bone plates, intramedullary needles, artificial joints, contraceptives, heart repair components, micropumps for artificial kidneys, etc.

High-tech application prospects:

The 20th century was the era of mechatronics. Sensing-integrated circuit-drive is the most typical mechatronic control system, but complex and bulky. Shape memory materials have the dual functions of sensing and driving, and can realize the miniaturization and intelligence of control systems, such as holographic robots, millimeter-level ultra-micro manipulators, etc.

The 21st century will be the era of materials electronics. Shape memory alloy robots are not affected by any environmental conditions except temperature, and are expected to be used in high-tech fields such as reactors, accelerators, and space laboratories.

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With the continuous progress of science and technology, more new technologies are used in the development of China's front-end science and technology. Some new processes have emerged, shape memory alloy materials are one of them, this new process has been used in China, the United States, Europe and other places, can expand the application of materials in a wide range, what is this material?Can the alloy return to its original appearance after deformation?

Let's tell you about it. <>

Shape memory alloy is a new type of material made of two or more multi-metal elements, which can produce changes under the interaction reaction of temperature and stress. It can be reversed by some of its properties: thermoelasticity and martensitic reciprocal reaction to produce a unique shape memory effect.

These cutting-edge technological features will be used in a wide range of applications, from aerospace to biomedical electronics. Shape memory alloy has also become one of the hot issues in various countries because of its uniqueness. The United States, Europe and other countries have been working hard to combine the production technology and composition ratio of shape memory alloy with advanced process technology, and have also achieved world-renowned results, and successfully applied it to aerospace and other applications, especially in 4D printers.

With its superior technology, SMA has become the raw material of printers. <>

In recent research, there are four main methods for the fabrication of shape memory alloys: smelting method, jet deposition method, and 4D printing technology. They all need to be configured according to the corresponding requirements to be able to continue the forging process as well as drawing, cold working, etc., so that the shape memory alloy can be formed.

Northwestern University has developed a remote-controlled walking robot using shape memory alloys, which can twist and bend, crawl and walk on its own to complete various difficult turns and jumps. <>

The development of global shape memory alloys in China actually started a little later, but the development process is relatively fast, and it has achieved a relatively leading level in many fields around the world. In the future, China will increase investment in R&D in this area and continue to promote the development and growth of shape memory materials.

Shape memory aluminum alloy is a new type of aluminum alloy material, and the aluminum alloy can be restored to its original appearance after deformation.

It is a special metal material with strong elasticity; Yes, it is almost possible to recover completely after tensile deformation, but it cannot be recovered after exceeding the limit.

It is possible to return to the way it was before. has his original memory, so it's called memory metal. This can be reverted to the previous one.