Patent Application
20100078412
The present disclosure is directed to a welding method and, more particularly, to a hybrid welding method.
Lasers are used in numerous industrial applications such as, for example, laser welding. A laser typically includes a pump source, a gain medium, and a mirror system. The pump source imparts energy to excite atoms of the gain medium. The excited atoms may then relax, emitting photons (i.e., light energy). The photons are reflected by the mirror system and travel repeatedly through the gain medium, concentrating the light energy. Stimulated emission may occur, where the photons affect atoms of the gain medium to emit additional photons having identical wavelength and phase, thereby producing laser light. A mirror of the laser may be partially reflective, allowing laser light to be emitted from the laser and used in an industrial application such as, for example, laser welding.
U.S. Patent Application Publication 2005/0011868 A1 (the '868 publication), by Matile et al., discloses a hybrid laser-arc welding method. The welding method of the '868 publication includes welding via a welding head including a laser and an electric arc. The '868 publication discloses using a YAG or CO2 laser.
Although the welding method of the '868 publication may provide a method for laser welding, the laser may not adjust to account for mismatch of work pieces. Additionally, the uneven energy distribution of a YAG or CO2 laser may negatively affect weld quality by focusing too much energy on certain portions of a weld and too little energy on other portions. Specifically, the laser disclosed in the '868 publication may allow the laser beam to shoot through a gap between work pieces to be welded, negatively affecting weld quality.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above and/or other deficiencies in existing technology.
In accordance with one aspect, the present disclosure is directed toward a welding method. The method includes making a weld via laser-arc hybrid welding. The method also includes using a fiber laser source in the laser-arc hybrid welding.
According to another aspect, the present disclosure is directed toward a welding system. The welding system includes a laser-arc hybrid welder including a laser welder coupled to an arc welder. The welding system also includes a fiber laser source.
Work pieces 115 and 120 may be any suitable materials for welding such as, for example, steel plates. Work pieces 115 and 120 may be between about 6 and 12 mm thick. Work pieces 115 and 120 may be placed against each other so as to leave no gap, or may be separated by a gap 130. Gap 130 may be about 1 mm or less in width. For example, gap 130 may be about ¼ mm to about ¾ mm in width, or about ½ mm or less in width. Weld 125 may be any suitable weld type such as, for example, a butt-weld joining work pieces 115 and 120.
Laser welder 105 and arc welder 110 may be separate welders mounted in separate places, or may be mounted on a single mount 135. Mount 135 may be moved at a suitable rate of movement for welding such as, for example, between about 1 and 2 meters/minute. Depending on welding conditions, either laser welder 105 or arc welder 110 may lead. Welding effects of laser welder 105 and arc welder 110 may be separated by a WLBD 142 (wire-to-laser-beam distance) of between about 0 and 20 mm. A position of laser welder 105 and arc welder 110 may vary during a welding process to generally match a change in position of work pieces 115 and 120 to be joined. The position of laser welder 105 and arc welder 110 may be controlled via automated programming. The programming of laser welder 105 and arc welder 110 may be adjusted during the welding process based on the change in position of work pieces 115 and 120.
Camera 300 may measure the conditions of a joint to be welded through the use of laser or visible spectrum technology. Measurements may be of gap 130 and any mismatch in alignment of work pieces 115 and 120. Upon measurement of the conditions of work pieces 115 and 120, the camera may feed information to laser welder 105 and/or arc welder 110 to change the welding conditions and/or the relative positioning in order to satisfy the changes. This may happen continuously during the welding process.
Arc welder 110 may be a gas metal arc welder (GMAW), also known as a metal active gas (MAG) welder. Arc welder 110 may include a consumable wire electrode 140 for generating a weld arc 145. Weld arc 145 may melt work pieces 115 and 120 and electrode 140 to make weld 125. A centerline 150 of arc welder 110 may be positioned at an angle 155 from an axis 160, where axis 160 is perpendicular to work pieces 115 and 120. Angle 155 may be any suitable angle for GMAW such as, for example, between about 20 and 45 degrees. Arc welder 110 may also emit shielding gas for protecting weld 125 during welding such as, for example, carbon dioxide.
As illustrated in
Gain medium 175 is a fiber laser source. Gain medium 175 may be an optical fiber that is doped with rare-earth-elements such as, for example, neodymium (Nd3+), erbium (Er3+), ytterbium (Yb3+), praseodymium (Pr3+), or thulium (Tm3+). Because it is a fiber laser source, gain medium 175 may affect the distribution of photons within laser beam 195, and may affect an energy distribution of laser beam 195 to be more evenly distributed. As shown in
The disclosed welding system may be used in any process where welding is required. The disclosed welding system may be used in all industries using welding, including manufacturing, remanufacturing, and repair applications.
In step 220, laser welder 105 may laser weld work piece 115 to work piece 120 at a desired location via laser beam 195. Laser beam 195 may melt and weld edges 206 and 208 of work pieces 115 and 120 together. As shown in
Step 225 may occur within a very short time of step 220 such as, for example, between about 0 and 100 milliseconds. In step 225, arc welder 110 may weld edge 206 and edge 208, and add metal from electrode 140, to make weld 125 at the desired location. As shown in
If gap 130 is greater than the threshold width, it may be determined to be wide and steps 235, 240, and 245 may be followed. When gap 130 is wide, the arc welding of step 235 may be performed prior to the laser welding of step 240. Steps 235 and 240 may be similar to steps 225 and 220, respectively. Steps 235 and 240 may produce a weld that is similar to finished weld 125 shown in
Steps 230 and 245 may occur within a very short time of 225 and 240, respectively. This step may be conducted using camera 300 or a different inspection technology to inspect weld 125. Steps 230 and 245 evaluate the conformance of the resulting weld to the engineering requirements.
Welding system 100 may employ laser-arc hybrid welding to produce weld 125. Camera 300 may be used to perform adaptive welding to make adjustments to the position of laser welder 105, arc welder 110, and work pieces 115 and 120 during the welding process. Camera 300 may adjust welding system 100 to account for mismatch of work pieces 115 and 120 and gap 130. Gain medium 175 may be a fiber laser source that produces laser beam 195 that produces weld 125 without voids. Laser beam 195 may melt edges 206 and 208 instead of shooting through gap 130. Using a fiber laser source may also produce an energy distribution more efficiently, thereby reducing costs.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed welding method. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed method and apparatus. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims and their equivalents.
