News

Shimadzu Corporation has achieved the world’s highest output of 6 kW for its BLUE IMPACT blue direct diode laser. Additionally, for the first time in the world with blue laser, “on-demand profile control technology” has been equipped that allows adjusting the shape of irradiation beam according to the processing target. This enables stable welding even at high power and realizes high-quality and high-throughput processing. The 6 kW output of the blue direct diode laser is approximately four times the output recorded in a NEDO (New Energy and Industrial Technology Development Organization) project in FY 2020.

With the shift to electrification of automobiles, major components are being replaced from the engines and transmissions to motors and batteries, leading to an increasing demand for processing pure copper materials with high electrical and thermal conductivity. Compared to the infrared lasers used in conventional laser processing, the blue lasers with a wavelength of 400 to 460 nm has a higher optical absorption efficiency for metals and are suitable light source for processing pure copper materials. In addition, diode lasers have superior response speed, remote operability, and maintenance-free compared to traditional lasers. Therefore, the blue direct diode laser is an indispensable tool for welding pure copper materials, which will be important for the widespread adoption of electric vehicles (EVs).

The 6 kW blue direct diode laser consists of a recently developed 1 kW blue direct diode laser and a unique processing head that combines the output light from 6 of the same laser devices. A rectangular core shape (200 um × 400 um) is used for the output fiber of the 1 kW blue direct diode laser. In the case of a conventional circular shape, there is a difference in heat transfer between the center and the periphery when scanning, but the rectangular irradiation shape allows uniform heating throughout the entire area and the high brightness with the expanded irradiation area realizing stable and high-speed processing. Moreover, the system implements the world’s first on-demand profile control technology, which independently controls the output power and beam irradiation position of each of the 6 bundled lasers. By controlling the laser beams to match the workpiece shape so that a strong beam is directed to the center of the  melting area and a weaker beam is directed around the center, the scattering of molten metal particles during welding can be suppressed, and high-quality processing can be achieved.

Shimadzu has been participating in a NEDO project on processing technology using high-brightness, high-efficiency lasers since FY 2016, and, working with professor Masahiro Tsukamoto of the Laser Materials Processing, Research Division of Materials Joining Process, Joining and Welding Research Institute, Osaka University, we have developed a unique technology for combining the output of multiple blue diode laser elements to achieve both the high brightness and high output power required of a laser processing light source. Shimadzu is currently collaborating with a major machine tool manufacturer to aim for the social implementation of this technology. Utilizing the BLUE IMPACT technology developed over the years, Shimadzu will develop a light source that can be used to weld EV motors, batteries, inverters, and other components.

• * “BLUE IMPACT” is a registered trademark of Shimadzu Corporation.

(a) Top view

(b)Bottom view

Example of high-speed penetration processing at 170 cm/min on a 3 mm-thick copper plate.
High-quality processing with reduced spatter is achieved by profile control.

(a) Example of welding flat rectangular
copper wire for a motor coil

(b) CT image

Example of welding copper flat wire for motor coils and non-destructive inspection of the welded area using a Shimadzu microfocus X-ray CT system. High-speed processing without blowholes (pores in the weld metal) was achieved for a 2 mm × 4 mm square wire.