How do laser welders work?

Laser welders are created using a gain medium (aka laser medium) and something that excites the medium to create the laser, such as a flash lamp or LED’s. The gain medium is the material that determines the wavelength of the laser and other properties – in the case of Alpha Lasers, the gain medium is a YAG crystal or Fiber Optic.

When the lasers in this case are created, the beam is guided to the workpiece through a set of mirrors, allowing laser welders to have a very high peak power, while having a very low overall heat input. Laser welders use this power to melt the base metal of the workpiece and filler wire in milliseconds, without adding extreme heat to the area surrounding the weld, as traditional welding would.

How is laser welding different from TIG(GTAW) welding?

TIG stands for Tungsten Inert Gas and is also referred to as Gas Tungsten Arc Welding, or GTAW. Laser welding has a few key differences from TIG(GTAW) Welding, including:

  1. Laser welders can weld a spot down to a few thousandths of an inch, while a TIG torch, even a Micro-TIG, cannot normally go below a .040” tungsten tip. This accuracy makes the laser able to weld areas or features that are traditionally unweldable while doing no damage to adjacent surfaces.
  2. Heat input. Laser welders pulse instead of running continuously. This creates a heat input so small that most welds are cool to the touch right after completion. With TIG welding, welded areas and materials get so hot that they need to have a post weld heat treatment, and need to be heated beforehand and cooled afterward at a slow rate so the base metal doesn’t damage itself during or after the welding process.
  3. Heat Affected Zone(HAZ). Along with the lower heat input, the Heat Affected Zone of Laser welding vs.TIG welding is considerably different. TIG welds can have HAZ as large as .150”, while the normal range for a pulsed laser is .008-.012”. This HAZ is the area that is damaged by the welding process, and the TIG welder can vastly reduce the hardness of the metal in the HAZ. The laser welder causes very little change.
  4. By the nature of how they create the weld pool, laser welders can join more dissimilar metals with more combinations than TIG welding.
  5. Laser welders can repeat a weld process, whether in automatic or semi-automatic modes, with extreme accuracy. TIG welding has a hard time replicating a process over and over, because of the variance in the tungsten and the arc.

What are laser welders used for?

Laser Welders can be used for many things, including repairing damaged parts, metal joining and weldments, automotive mold repair, engineering changes and more. Laser welding can be used anywhere traditional welding (TIG) can be used, with excellent results and longer lifecycles for welded parts.

How accurate is laser welding?

Laser Welding is extremely accurate, using a microscope and joystick to control the laser beam and weld location. The laser process can reach weld spot sizes as small as .004.

What is the heat input of pulsed laser welding?

Pulsed laser welding has an extremely low heat input and often, a part is cool to the touch immediately after welding. The laser pulses release high energy, but in a very short time period, allowing the laser to melt the metals, but not infuse more energy than it needs to into the workpiece. Because of this low heat input, laser welding does almost no damage to the base metals and can be used to complete repairs and welds on parts that were previously thought to be un-weldable because of size and shape constraints.

How repeatable or scalable is laser welding?

Alpha Laser welding systems have CNC capabilities (Computer Numeric Control), allowing production and high-volume welding processes to be completed quickly and with great precision.

What industries use laser welding?

Laser welding can be used in every manufacturing sector from Tool & Die, Automotive, Aerospace, Defense, Electronics, Automation, Medical/Healthcare, Oil & Gas, Energy & Power, Transportation, Additive Manufacturing, and more.

How hard is it to operate a laser welder?

Laser welding is easier to pick up than traditional welding but takes many hours of practice to master. Alpha Laser includes a training package with each system, specifically tailored to the end user of the laser system.

What is the largest welding rod that can be used with Alpha Lasers?

Alpha Laser welders can use up to .040” (1mm) welding wire, but traditionally are more efficient and faster when using wire that is .020” (.5mm). With a higher Hertz rate, the Alpha Laser welder can apply material much faster than other lasers, and maintain the laser welding benefits.

What materials can you weld with a laser welder?

Lasers can weld a wide range of metals including cast iron, nickel-based materials, tool steels, stainless steels, super alloys, copper alloys, and many others. Because the laser welding process is pulsed, it can be used on previously un-weldable materials, as it has immediate quench, creates little heat on surrounding parts, and doesn’t cause as much stress on the welded parts.

How much heat does a laser welder produce?

Laser welders produce very little heat, especially when pulsed. Pulsed laser welders can put so little heat into a part or assembly that it is cool to the touch immediately after welding. Traditional welding methods create a very large heat affected zone (HAZ) around the weld, and the intense level of heat can damage welded parts.

Can you laser weld seams and joints?

Yes. Laser welding is used for joint and seam welding, normally in sheet metal joining. Laser welding is a great process for sheet metal, as the lower heat decreases potential rework or polishing on the seam.

Can you laser weld dissimilar metals?

Yes, laser welding dissimilar metals is a common process. Laser welding is superior for joining dissimilar materials, as the dilution rate is very low, but the bond is an excellent metallurgical one. Common dissimilar applications include tool steels, superalloys, coppers, and many other materials.

Can you use a laser welder to repair damaged parts?

Yes, a laser welder can be used to weld damage parts. If something is damaged, laser welding can be used to bring it back into tolerance, with minimal to no distortion or damage, and with very little rework.

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