Laser Hardening

Laser Hardening is a heat treatment process which uses a high power laser beam to locally harden the surface of steel or cast iron components.

 

Being similar to induction hardening, laser hardening relies on the thermal mass of the component to quench the area to be treated. There is no need for quenching in water or oil to achieve the hardness you require.

 

Lasers tend to produce harder surfaces to a shallower depth compared to other hardening processes. This makes laser hardening ideal for improving the performance of intricate and high accuracy components.

 

One major advantage of laser hardening is that it does not affect the surface finish of the component. This means laser hardening can be conducted on finish machined components, without the need to re-machine afterwards.

 

Typical examples include the edges of blanking and pressing dies, the edges of cams and gears.

 

Important considerations for laser hardening are:

 

Substrate Material:  Only materials which undergo transformation hardening can be hardened by this method, carbon steels, high carbon stainless steels, cast irons and aluminium bronzes are typically considered hardenable.

 

Surface finish: The absorption of the laser light into the substrate must be accurately controlled, the surface roughness and finish can dramatically influence the amount of laser energy which is reflected, therefore extremely reflective surfaces are very difficult to laser harden.

 

Depth of hardness: Laser hardening can be used to produce a hardened layer upto 1.5 mm into the base material. In general, deeper hardening results in lower hardnesses.

 

Impact and toughness: Laser hardening is capable of producing extremely hard microstructures sometimes over 1000 Hv, with this comes loss in ductility if your application demands high levels of toughness then perhaps laser cladding is a more suitable option.

This Video Shows the cutting edge of a D2 tool steel piece being laser hardened.

This Video Shows the cutting edge of a D2 tool steel piece being laser hardened.

This Chart shows the hardness profile of Laser hardeded D2 tool steel

This Image shows a cross section through the microstructure of Laser hardened D2.

The lighter structure is the laser hardened zone

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