Advances in Laser Welding Technology

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1 Advances in Laser Welding Technology How an upgrade to laser welding lowers cost per part, improves part quality and reduces delivery time. Jay Reddick Laser Welding Development Manager Estes Design and Manufacturing, Inc., Indianapolis, IN Faster. Cheaper. Better. Laser welding uses the extremely high power density of an industrial laser, concentrated in a small spot size that cannot be matched by conventional welding methods, to melt metal parts and create a highly stable and resilient joint between them. Laser welding iss the wave of the future, and companies that are often called upon to fabricate complex parts have bypassed conventional 2D laser welding machines, and opted instead to invest in advanced technology like the Prima robotic laser welding system with a 5-axis CNC gantry robot capable of welding even the most complex 3-dimensional parts.

2 Why Laser Welding? In sheet metal work the most commonly used, traditional welding processes are metal inert gas (MIG) welding and tungsten inert gas (TIG) welding, both of which use electric current to bring the primary substrate to the melting point, to which is added a filler metal to complete the weld. Both methods are rather slow typically 7-10 inches per minute (ipm) for TIG and ipm for MIG. Depending on the type of weld required, the speeds achievable with laser welding can reach 40 times faster than TIG welding and 10 times faster than MIG welding, which boosts productivity and drives down labor costs savings that are passed along to customers. Additional savings arise from the reduction, or total elimination of grinding and sanding operations required by MIG and TIG processes. The filler metal used in conventional welding methods causes a metal buildup, which depending on the cosmetic properties required of the finished part, normally involves these secondary finishing processes. This adds both time and expense to part production. With laser welding, secondary cleanup operations to remove weld buildup is not required, saving both time and money.

3 The photo above demonstrates the difference between laser welding and traditional methods. Compare the laser welded panel at left to the conventionally welded panel (center) that had to be finish ground to achieve the result at right. The welds left and right are equivalent in quality, but an extra (costly) step is required to complete the finished product. Consistent part quality is always a manufacturing concern, and in any MIG or TIG welding operation, final product quality can vary widely, depending upon the skill and fatigue factor of the individual operator. Automated laser welding eliminates the human variables, making repeatable part quality the norm rather than the exception. Here is a real world example of what that speed, coupled with the laser's pinpoint accuracy, can mean to you: One project that Estes Design and Manufacturing, Inc. undertook for a major appliance manufacturer required a 10 weld of 16 gauge cold rolled steel. With traditional TIG welding, the cost to the customer would have been $5.84 per unit. Using the new 3D laser welding system to reduce cycle time, Estes was able to not only increase speed, but also to eliminate the grinding and sanding operation. The unit cost to the customer was reduced to $0.96. Here are the numbers: Traditional TIG Welding 3D Laser Welding Weld speed 5 in./minute 160 in./minute Cycle Time 2 minutes minutes Grinding/Sanding Time 2.95 minutes 0.00 minutes Total Cost Reduction 0% 84%

4 Cosmetic appeal is important to most of Estes customers and here again, laser welding makes a major contribution. The HAZ, or heat affected zone in fabricated and welded components is a problem that welding professionals and part designers have been struggling with for years. HAZ results from the buildup of heat at the weld point, which creates an area surrounding the weld that is adversely thermally affected in two major ways: One: Warping, which is likely to occur across the entire weld area due to the heating and cooling cycle; Two: Discoloration of the weld and surrounding area due to exposure to the atmosphere as the weld slowly cools. Due to the precise transfer of heat within the laser weld area, and the speed at which the welding is completed, both of these characteristics are minimized, if not entirely eliminated. 3D Laser Welding reduces or eliminates the need for post-weld grinding or finishing, saving time and decreasing labor costs, and it also improves the functionality and integrity of the part. An aspect of laser welding that is not often mentioned is the fact that despite its high tech nature, the process is inherently versatile. That s because it doesn t require access to the opposite side of the weld point as does resistance or spot welding. This is particularly important in hermetic welding of enclosures. Also, the quality of the laser weld is remarkably consistent aside from environmental or joint variation issues. About Estes Design and Manufacturing, Inc. It is for the reasons included in this white paper that we at Estes have applied the laser welding process to parts for the appliance, medical,

5 food service and office furniture industries, resulting in consistently distortion free and cosmetically superior welds, even with butt welds in material as thick as 3/16-in., which are capable of being performed with 100% penetration. Today, Estes employs a staff of more than 80 skilled associates, and its manufacturing facility is housed in 50,000 square feet to provide even the largest companies with quality products and services. Estes has made it a priority in the past several years to acquire the latest fabricating technology. Using automation when it adds value to the process ensures customers the most cost-effective solutions to the challenges of manufacturing. In the highly competitive world of sheet metal product fabrication, job shops win and retain business on the basis of a reputation for honesty and promises kept, quality of finished products, fair product costs, and on-time delivery. Estes Design & Manufacturing has grown and thrived, even in a down economy, because of its faithful attention to each of these details. Reputations are earned over time through integrity and the ability to deliver what is promised principles that have guided Estes since its founding in High quality products are the result of a continuing investment in high technology and training dedicated, qualified people to operate the lean manufacturing systems found on Estes shop floor. Competitive product costs and on time delivery are the result of savvy harnessing of the best technology and lean practices by smart people. Never timid about pulling the trigger when it comes to adding new technologies that can bring increased value to its customers, Estes

6 Design and Manufacturing has added 3D laser welding to its arsenal of manufacturing capabilities.