Tungsten Alloy Additive Manufacturing Technology: Laser Selective Melting For...

2024-01-05 18:05:21

Tungsten Alloy Additive Manufacturing Technology: Laser Selective Melting Forming Technology

Dec 20, 2019

The European Space Agency said that metal additive manufacturing technology, also known as 3D printing technology, can be used to make a tungsten alloy component that can withstand 3000 ° C used in nuclear fusion reactors and rocket nozzles.

Among them is a "Mysterious" Laser Selective Melting (SLM) technology that the United States asked China not to leak. Why was the US so nervous then? What kind of technology is this?

At that time, the reason why the United States felt nervous might be because their NASA had just successfully implemented the SLM technology in the previous year. They also claimed to be the leader in the application of the technology in the aerospace field. "Laser Selective Melting and Forming Technology" successfully passed the acceptance test. To the extent that the United States even directly issued a document, "requested" China not to disclose this project document too soon.

So, what exactly is laser selective melting technology?

Laser selective melting forming technology is a large category of metal 3D printing technology. It was first proposed by a laser technology research institute in Germany in the 1990s.

Institutions studying the technology in China include Huazhong University of Science and Technology and South China University of Technology.

SLM technology can make physical parts based on the three-dimensional model data of parts or objects, through molding equipment and material accumulation.

It breaks the traditional tooling, fixture and machine tooling process.

It can solve the processing and manufacturing problems of porous, hollowed out, dot matrix and other lightweight complex structural parts that are difficult to be solved by traditional manufacturing technology.

It can provide a new way to solve the problem of weight reduction design and manufacturing of complex structural parts in a wide range of manufacturing fields such as aerospace, automotive, shipbuilding, energy, chemical, and medical industries in China.

As we all know, the wide application of a new technology naturally has its advantages, so what are the advantages of SLM molding technology? It can prepare high-precision parts; it can greatly shorten the life cycle of the product; it has good mechanical properties, mechanical properties and strong corrosion resistance; the powder used in the process can be reused to save materials.

At the same time, the birth of a new technology necessarily has imperfections. So, what are the shortcomings of SLM molding technology?

The manufacturing cost of the machine is high. At present, the price of foreign equipment is more than five million. Due to the limitation of the laser power and the deflection angle of the scanning galvanometer, the size range of the parts that can be formed is limited. During processing, spheroidization and warpage are easy .

However, why use laser selective melting forming technology to prepare tungsten alloy parts instead of traditional powder metallurgy?

Because tungsten has a relatively high melting point and low temperature brittleness, general casting and machining methods cannot be used to prepare tungsten or tungsten alloy materials. Even if powder metallurgy is used, the conventional sintered tungsten materials will have a density. Low, low strength, poor plasticity, and difficult to control impurity content. Moreover, the structure of tungsten material parts has characteristics such as curved surfaces, holes, grooves, and curved pipes. It is difficult to achieve even by powder metallurgy. Therefore, it is natural to adopt new forming technology. At present, laser selective melting technology is used to additively manufacture tungsten and tungsten alloy materials.