Laser Beam Welding (LBW) is an advanced technique that uses a narrow beam of light to join pieces of metal. Laser welding is used to fuse parts by forming a pool of liquefied metal at the junction point where two pieces of metal meet. This technique is better than most for joining dissimilar metals and those that are typically difficult to weld.
The laser beam provides a concentrated heat source, allowing for narrow, deep welds and high welding rates. The process is commonly used for its precision and the ability to control the weld due to the focused beam's small spot size.
LBW offers several advantages over traditional welding methods such as Gas Tungsten Arc Welding (GTAW), which is sometimes referred to as TIG or Tungsten Inert Gas Welding. Benefits of LBW offers include more precise control over the width and depth of weld; less distortion of the workpiece because LBW generates less heat; ability to weld at higher speeds, allowing manufacturers to increase productivity; greater versatility that allows it to be effective on a wider variety of metals; and more easily automated with robotic systems, which improves repeatability and throughput.
Applications Abound
LBW is used in the automotive industry to manufacture gear assemblies, transmission parts, and other components. It is also used in the aerospace industry to fabricate high precision lightweight structures and components. Electronics manufacturers deploy LBW to join small parts in electronic devices where traditional welding could damage sensitive components and
medical device manufacturers use it to assemble intricate products such as pacemakers and surgical tools or instruments.
How LBW Works
In LBW, a laser generates a highly concentrated beam of light that is focused onto the material to be joined. This intense heat source melts the material in a small area. The molten material then flows together and solidifies, forming a strong joint upon cooling. The process can be conducted in air or under a vacuum and typically uses a shielding gas like argon or helium to protect the molten weld pool from oxidation and atmospheric contamination.
The key steps in LBW are Preparation – cleaning and precisely aligning the surfaces to be welded; Equipment Setup, which includes configuring the laser parameters like power, pulse frequency, and beam size; Welding by directing the laser beam at the joint area manually or by using a computer-controlled system that rapidly heats and melts the material;
Shielding, which consists of using a shielding gas to protect the weld area from environmental contamination; Cooling the melted material that solidifies to form a weld; and Post-Processing such as grinding or machining to finish the weld.
Types of LBW
There are several common types of LBW. Conduction Welding uses the lowest power rating of any LBW technique. It merges the melted edge without filler, using capillary action exclusively. This approach is ideal for welding precisely fitted edges of thin materials.
Deep Penetration Welding is well-suited to welding thicker materials. It uses a large amount of laser power to penetrate deeply. The laser generates a column of vaporized metal (keyhole) that penetrates the material’s full thickness. The keyhole closes as the beam passes by and the column of metal vapor recondenses.
Laser Spot Welding is ideal for small, complex parts because the laser creates small, localized welds that can make “point joints” between edges or melt through one part to fuse with another part.
A Brief History
LBW was developed in the 1960s while lasers were becoming important in the field of electronics. Researchers at Bell Telephone Labs in New Jersey (now Nokia Bell Labs) conducted the first laser welding experiments. Those welds were made with a ruby laser that applied short pulses of high-intensity energy in coherent beams. When pulses were focused onto a small spot at the junction of metal parts, the metals melted and flowed together.
Those early experiments resulted in the creation of extremely narrow and precise welds with minimal HAZ (heat-affected zones) and distortion and demonstrated some ability to join dissimilar materials.
How Advance Welding Can Help
We use modern CNC motion control technology to produce the highest quality welds for medical devices, automotive applications, sensor assemblies, and other uses. Our laser welding equipment includes an IPG 2kW Continuous Wave Fiber Laser and a LaserStar 7000 Series Pulsed Laser. The laser’s motion is controlled with 4-axis CNC machine along with a high-performance galvanometer scanner.
The range of components we laser-weld include combustion cases, combustion liners, high-pressure turbine (HPT) cases, low-pressure turbine (LPT) cases, aviation ground support equipment, aviation bearing seal assemblies, aviation engine handling fixtures and tooling, NAVSEA ship components, ground-based gas turbine components, aircraft engine components, and satellite thrusters for positioning.
The common and specialty metals we weld include carbon and alloy steels (A36, 1018, 1020), heat treatable alloy steels (4130, 4140), stainless steel (304, 316, 410), precipitation hardenable stainless steel (13-8Mo, 15-5PH, 17-4PH), nickel and nickel-based alloys (Monel 400, Inconel 625, Hastelloy X), precipitation hardening nickel & nickel-based alloys (Monel K500, Rene 41, Inconel 718) non-heat treatable aluminum alloys (5052, 5083, 5086), heat treatable aluminum alloys (355, 356, 6061), magnesium alloys (AZ31B, AZ91A), titanium alloys (Grade 2, 6Al4V), and copper alloys, and cobalt-based alloys.
Examples of Our Work
In one instance, we used our laser welding capabilities to help a Mississippi-based manufacturer produce 30,000 assemblies for an air conditioning application. The assembly process consisted of laser welding and electron beam welding. We cleaned, assembled, laser tacked, and electron beam welded each assembly 360 degrees circumferentially.
Using CNC equipment for tracking, we welded each piece to a penetration depth of .030"-.040". Part dimensions were 1.75" long and 2" in diameter. After we completed the welding, we performed pressure testing and helium leak testing on the parts before shipping them to the customer.
On another occasion, we manufactured a double-spring assembly for an automotive industry customer. processes ensured accurate and repeatable quality throughout the entire run.
This assembly consisted of two stainless steel springs fabricated from .065” diameter wire. Operations involved winding the two springs together and preparing the surface for welding by cleaning it with acetone.
Our CNC-controlled 4-axis laser welder, equipped with a high-performance galvanometer scan head, allowed us to maintain precise positioning while achieving fast cycle times. When completed, the assembly measured approximately 1.5” in length x 1.5” in width. Visual inspection at 10x magnification confirmed we met the ±.005” tolerance called for in the specification.
Our technical expertise, along with in-house tooling, allowed us to complete this multi-component assembly with a quick turnaround time, and we continue to produce this precision product at the rate of 30,000 units a year.
If your laser welding application involves components for aerospace, automotive, medical devices, electronics, government laboratories, industrial, defense, oil & gas, power generation, sensors, telecommunications, or vacuum equipment, chances are excellent that we have similar or identical experience that can benefit you. To discuss your specific requirements…
