PL196404B1 - Laser welding process for welded joints on aluminium and its alloys - Google Patents

Abstract

A method of laser welding of joints made of aluminum and aluminum alloys using a laser, characterized in that the welding is performed using a high-power diode laser using a pool technique, wherein the joint area is covered with a substance used for TIG welding of butt joints of austenitic steel sheets with a high penetration depth.

Description

REPUBLIC

POLAND

Patent Office of the Republic of Poland (12) PATENT DESCRIPTION (19)PL (11)196404 (13) B1 (21) Application number: 346354 (51) Int.Cl.

B23K 26/24 (2006.01) B23K 26/18 (2006.01) (22) Date of submission: 07.03.2001 (54) Method of laser welding of joints made of aluminum and aluminum alloys

(73) Patent holder: (43) The application was announced: Silesian University of Technology, Gliwice, Poland 09/09/2002 BUP 19/02 (72) Inventor(s): Andrzej Klimpel, Gliwice, PL (45) The patent was granted on: 31.12.2007 WUP 12/07 (74) Attorney: Urszula Ziółkowska, Silesian University of Technology

⁽⁵⁷⁾ A method of laser welding of joints made of aluminum and aluminum alloys, using a laser, characterized in that the welding is performed using a high-power diode laser with a pool technique, wherein the joint area is covered with a substance used for TIG welding of butt joints of austenitic steel sheets with a high penetration depth.

PL 196 404B1

Description of the invention

The subject of the invention is a method of laser welding of joints made of aluminum and aluminum alloys.

Welding aluminum and its alloys using high-power CO2 gas lasers and N:YAG solid-state lasers has been used in industry worldwide for many years. However, due to the very low energy absorption coefficient of the laser beam, welding is only possible using the "eyelet" technique or with the use of special substances that enhance laser absorption. Diode laser welding of aluminum and its alloys is not used in industry because the welded joint can only be made using the "pool" technique, and the use of a substance that enhances laser absorption ensures very shallow penetration depths.

The method according to the invention consists in welding using the pool technique using a high-power diode laser, wherein the joint area is covered with a substance used for TIG welding of butt joints of austenitic steel sheets with a high penetration depth, e.g. ActivaTec by Castolin.

As a result, high-quality joints of aluminum and its alloys were obtained, with a penetration depth more than twice as great as in the case of using substances increasing the absorption of laser radiation used so far in laser welding of aluminum and its alloys.

Example.

A butt joint of 3.0 mm thick AI3Mg aluminum alloy sheets was welded using a high-power ROFINDL 020 diode laser. Prior to welding, the upper surface of the joint area was coated with a thin layer of Castolin's ActivaTec 500. A 2.0-2.5 kW laser beam was focused on the upper surface of the welded sheets at a focal distance of 82 mm. Welding was performed using the weld pool technique at a speed of 0.5-0.8 m/min under argon shielding, resulting in a joint with full penetration and mechanical properties equivalent to those of the welded AI3Mg alloy sheets.

Claims (1)

Patent claim A method of laser welding of joints made of aluminum and aluminum alloys with a laser, characterized by the fact that it is performed with the weld pool technique using a high-power diode laser, where the joint area is covered with the substance used for TIG welding of butt joints of austenitic steel sheets with large remelting depth. Publishing Department of the Polish Patent Office