Beyond Lasers! Breakthrough in Electron Beam Route for Metal 3D Printing

3D printingTechnology, belonging to the new round of scientific and technological revolution as well as industrial change with significant driving force. During the Zhongguancun International Technology Trade Conference in 2024, Tsinghua University's Tsingyan SmartBeam, a company formed after the transformation of its scientific and technological achievements, released a brand new electron beam 3D printing product, whose related technology is significantly different from the mainstream technology route in this field today.

2024 Zhongguancun International Technology Exchange Conference.

Electron beams and lasers

3D printing technology, also known as additive manufacturing technology, is a new technology that uses digital model files as the basis, using powdered metals or plastics and other adhesive materials, point by point, layer by layer, cumulative superposition and thus the formation of three-dimensional entities. It has become one of the important driving forces of the new round of technological revolution and industrial change because it has a profound impact on the traditional industrial processes, production lines, production modes, and industrial chain combinations.

3D printing is divided into metal 3D printing and non-metal printing, of which, metal 3D printing mostly iron, titanium, nickel, steel and other metal powders as raw materials, the existence of customisation, low-loss, precision manufacturing and other advantages, in the aerospace, military, medical devices and other manufacturing areas that have stringent requirements for product performance is widely used, compared with non-metal 3D printing, metal 3D printing has more value, Compared with non-metal 3D printing, metal 3D printing has more value, higher technical barriers and more space for future applications.

A research report shows that in the metal 3D printing of a variety of technical routes in the category, the laser selective melting technology, also known as SLM, is the main popular programme, the output of its products in the cost-effective relatively dominant position, and the degree of difficulty of the technology is also relatively in the moderate situation.

Lin Feng, a long-time professor at Tsinghua University's Department of Mechanical Engineering, said that in the aerospace sector, there is a growing demand for additive manufacturing of high-temperature metals as flight parameters continue to improve. Super-combustion ram engine inlet, gas turbine turbine blades, solid rocket engine throat liner, high-super vehicle end of these parts, their operating temperature are more than 1000 ℃. High-temperature metal materials are difficult to shape accurately and are prone to cracking with laser printing, but the problem of cracking can be solved with the use of electron beam selective zone melting (EBSM) technology.

There is a technology, which uses a high energy electron beam as a heat source, which is based on a powder bed, CAD which is also known as computer aided design directly driven near-net-shape metal additive manufacturing process. Because it has a higher energy conversion rate as well as absorption rate and less internal stress, it forms better. He speaks, “Materials that would have cracked are now able to not crack; structures that would have needed to be designed with very strong supports are now able to be unsupported.” .

Multi-gun array technology breakthrough

Compared to lasers, the electron beam route to metal 3D printing is superior in terms of overall performance. However, because E-beam requires a vacuum environment, this technology is more difficult to develop and has lagged behind for some time.

Tsinghua University and the Tsinghua University SmartBeam team have been working hard on this route for 20 years. In 2004, the team members successfully developed the E-beam selective melting technology at Tsinghua University; in 2015, Tsinghua University incorporated Tsinghua Wisdom Beam; in 2017, the first generation of commercialised equipment was independently developed; in 2021, the Qbeam series of products will be launched; and in 2023, the multi-shot array equipment will be released.

Multi-gun array equipment.

Dr Zhao De Chen, R&D Director of Beijing Qingyan Smart Beam Technology Co., Ltd, and a doctor at Tsinghua University, said that the technical team found that there are limitations to the size of the electron beam additive manufacturing equipment that exists in the market today, which is a key constraint to its production applications in the aerospace field. “Currently, the mainstream commercial E-BEAM equipment at home and abroad does not exceed 400mm in size; however, the reality is that many aerospace titanium alloy parts exceed 500mm in size.” .

In order to reach the solution of large-size titanium alloy parts to achieve batch production, the technical team selected the multi-gun array technology, and since the beginning of 2018, accumulated more than 20 key technologies to solve the multi-gun interference, multi-electron beam splicing calibration, etc., and successfully developed a new Qbeam S600, the product fits the aerospace and aviation requirements for high-efficiency, low-cost batch manufacturing of large-size and structurally complex components, and the print The product meets the requirements of aerospace and aviation for large-size, structurally complex components with high efficiency and low-cost batch manufacturing, and the print size has been expanded to 600×600×700mm, and the deposition efficiency of titanium alloy has been increased to more than 400 cubic centimeters per hour.

The e-beam machine has significant batch production economies compared to laser machines, with a typical part for a medical application dropping 471 TP3T in cost per part and increasing machine output to 2001 TP3T.

Technology Leadership.

As far as he knows, Zero2IPO is the only equipment manufacturer in the world that has carried out research on multi-gun arrays and realised industrialisation, said Zhao De Chen.

He made a statement, clear research wisdom beam has been controlled by the electron beam 3D printing multi-gun array of a set of core technologies, a variety of larger size equipment in the research as well as has completed the project acceptance stage, multi-gun array technology, may open up a whole new chapter of the electron beam additive manufacturing.

Editor-in-chief: Fan Jianghong