Laser heat treating – a short course

Maybe you’ve heard a little about laser heat treating and you think it might be all smoke and mirrors. Or, maybe you’re surprised a laser could be used for something other than cutting metal, and you’d like to know how it might benefit your operation. Either way, the technology is tried and tested in multiple applications in nearly every industry in America.

Here’s how it works.

Laser heat treating is much the same as any other thermal hardening process, except that it uses the highly controllable energy of a CO2 laser. Regardless of the energy source, the object is to raise the temperature of the piece to the point where its internal structure begins to crystallize (the transformation temperature), then allow the piece to cool rapidly.

In conventional case-hardening, the cooling (quenching) is hastened by chilling the piece with oil, water, or forced air. When treated by laser, the workpiece can usually be self-quenched, or cooled in ambient air.

Used at full intensity, the laser is able to cut through a metal piece. Reduce the energy somewhat, and the beam melts the surface, making it possible to weld–or to create a tough clad coating. Reduce the beam energy further, or shorten its duration, and the surface is only heated; if brought to the transformation temperature, then cooled, the surface becomes harder than before.

A laser beam causes very rapid heat input into a small area of the work-piece. There is rapid transformation, then an extremely high cooling rate, as the heat is conducted into the workpiece by its own mass. The real advantage of this type of heat treating lies in the uniformity of the method and the precise control of the depth of the hardened area.

The depth of hardening is determined by a number of factors. The slower the treatment speed, the deeper the hardening effects. Power density and treatment speed determine the actual heat input into the workpiece surface.

BMR Group has over two decades of experience in laser heat treating. We know what works and what doesn’t. Because we offer multiple hardening technologies to fit applications across most industries, you can be sure we’ll help you select the best technology for your components and your operating environment.

BMR Group has more expertise and experience with laser materials processing than any other company in the business. Need proof? Look at these articles.
The Art & Science of Laser Heat Treating
Job Shop Laser Heat Treating
Toughening Up Capstan Surfaces

If you have components that require case hardening and you’re tired of problems of distortion and failure, call BMR Group at 260-635-2195 and discover how easy it can be to gain the advantages of laser heat treating.


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