In July 2020, TRUMPF exhibited the latest copper and precious metal 3D printer-TruPrint 1000 green version at TCT Asia, which attracted great attention from the industry. This unique green light 3D printing device in the world can Provide more stable and efficient pure copper, copper alloy and precious metal processing technology to serve additive manufacturing.
However, there are still many interested Xiong friends who have doubts about green light 3D printing technology and application points. This time Hay Think will take you into the laser application center of TRUMPF and let TRUMPF's The engineer will explain to you on site.
TRUMPF's laser metal melting additive manufacturing laboratory in Taicang, Jiangsu
This time we invited an application expert who has studied in the field of 3D printing for many years-Manager Li Zhonglun of TRUMPF Asia Pacific Additive Manufacturing Center, and asked him to serve as the chief commentator to answer questions.
In the TRUMPF Additive Manufacturing Laboratory, four 3D printing devices were installed, including two TruPrint 3000, one TruPrint 1000 dual laser version, and the TruPrint 1000 green light version that just came out.
In addition, TRUMPF’s own unpacking station and powder sieving machine were installed, as well as two industrial explosion-proof vacuum cleaners and three powder sieving machines produced by its partner Jiaxing Tuobo.
This time I will focus on this TruPrint 1000 green version. As we all know, metal 3D printers are mainly composed of lasers, optical transmission units, control systems and other parts. Lasers are the core components that directly determine the quality of metal 3D printed parts. At present, metal 3D printing equipment at home and abroad mainly uses infrared fiber lasers with a wavelength of 1064 nanometers, while the green version of the TRUMPF TruPrint 1000 uses a green laser TruDisk 1020 with a wavelength of 515 nanometers.
Due to the very high thermal conductivity and reflectivity of copper, this makes it difficult for copper metal to be shaped effectively by conventional 3D printing. The absorption rate of near-infrared light of copper at room temperature is only 5%, which means that the processing window is very high. It is difficult to find perfect parameters, and the processing efficiency is very slow. The mechanical properties and electrical conductivity of the parts are greatly restricted. In addition, 95% of the energy reflection is also very harmful to the equipment itself. Copper has a high absorption rate of green lasers, close to 40%, which is 8 times that of near-infrared lasers. A good absorption rate means relatively wide processing. The window, mechanical properties and electrical conductivity of the part are greatly improved, and the reduction of reflectivity can make the processing process more stable and efficient.
Copper metal 3D printing technology is mainly used in the aerospace field. However, the high threshold in these fields has discouraged many companies engaged in metal 3D printing services.
In fact, for copper 3D printing, there are still many applications in the civilian industry, which can just take advantage of the characteristics of copper and the flexibility of 3D printing. Manager Li Zhonglun cited several cases for us.
Heat exchanger
The integrated 3D printed heat exchanger has been optimized in design and no longer requires assembly and welding, but integrated processing. 3D printed heat exchangers are lighter and more efficient than heat exchangers made by other methods.
Electric sensor
Generally speaking, the inductance coil in the electric inductor needs to go through several mechanical manufacturing processes. The coil is manually bent and welded to achieve the desired shape. This is a test of the worker’s handwork and experience. Each solder joint will change the current and cause Performance drops significantly. In addition, the performance of the inductor coil is also limited by the geometric shape. The traditional manufacturing process can usually only achieve relatively simple shapes, while 3D printing can make the inductor coil more compact and complex, thereby achieving higher efficiency. Compared with traditional manufacturing, the service life of 3D printed electric sensors has been significantly improved, which can reduce the frequency of replacing electric sensors and save costs.
Take the chrome pick copper powder produced by Heraeus as an example, and use the TRUMPF TruPrint 1000 green plate to process several key mechanical properties. Among them, the relative density can reach more than 99.5%. After the sample is heat treated, the tensile strength in the 90-degree direction can reach 470 MPa, the elongation rate can reach 26%, and the electrical conductivity at room temperature is 81%.
However, the chrome pick copper workpiece processed by conventional infrared laser has a tensile strength of 380 MPa, an elongation rate of 15%, and a conductivity of 75%.
This is the T1 pure copper produced by the Austrian m4p company. It has several performance indicators after printing with the TruPrint 1000 green plate. The electrical conductivity can reach 100% of the international annealing copper standard, and the density can reach 99.5% or more. From the printing parameters It can be seen that the laser power of 485 watts can correspond to the scanning speed of the galvanometer of 600mm/s, which reflects a very high processing efficiency.
Finally, Manager Li Zhonglun said: TRUMPF welcomes friends who are interested in green light 3D printing technology to visit and communicate with TRUMPF China Additive Manufacturing Laboratory in Taicang, Jiangsu, to develop the most suitable process plan for you. And invite 3D printing high-quality powder suppliers across the country to contact TRUMPF (China), and work together to provide customers with high-quality services.