Laser Hardening

Laser Hardening Practice

Laser hardening replaces heat treating methods that typically affect the whole surface of the part (furnace heat treating) or a large portion of it (flame hardening), allowing only the specific areas exposed to the laser beam to be hardened. Laser heat treating also allows for exacting control of the heat input to the treated surface by varying the laser power and the speed with which the heat is applied. The result is that hardening is achieved where it is needed, and the part retains its natural strength and ductility where it is not.

Laser Hardening Applications

Firearms

Mechanical components most susceptible to wear, such as hammers and slides, are often manufactured from tough and durable high performance corrosion resistant alloys. These materials are often well suited to heat treating, which can substantially extend service life, fit, and action without adversely affecting ruggedness and durability.

Airfoils

Tip and leading edge erosion are a common cause of failure or steam and gas-powered turbine blades. Hardening is a cost-effective alternative to costly cobalt super alloy erosion shields, and laser hardening ensures that the heat treating process does not compromise the blade’s ductility.

Pumps and Valves

Seal rings, glands, seats, and other high-friction mating areas of mechanical fluid handling components can benefit from hardening that will reduce wear and extend service life without introducing distortion or affecting fit.

Laser Hardening Application Criteria

Laser hardening requires parts to be manufactured from heat treatable, hardenable alloys such as 400-series stainless steel, Inconel, or high carbon steel. The time and temperature curves of these materials will dictate the range of hardness achievable by heat treating, and, for low-distortion applications, it is prudent to select a target hardness somewhat below the maximum achievable. Unlike furnace or flame hardening, laser hardening is a line of sight process, and so the surface to be treated must be directly visible. Unlike laser cladding, standoff is not critical; even deep surfaces can be hardened, provided there is a direct line of sight.