Laser hardening offers many advantages over conventional heat treatment processes - the economical aspects include a high throughput, reproducibility and product quality. In many applications, localized treatment and minimal heat input results in reduced distortion and the rapid quench rates produce a fine microstructure.
Sheet metal forming tools
All surfaces in contact with the sheet materials can suffer from wear, particularly in the radius regions where high contact pressures and sliding occur. Laser hardening of these areas offers a real alternative to flame or induction hardening where distortion or reliability often presents problems.
Laser hardening is ideally suited for contact surface hardening where the precise application and fast treatment times lead to minimum heat input, reducing distortion to a minimum. The flexibility of the laser equipment allows for hardening of a wide variety of tool shapes.
Plastic injection moulds
An increasing application of laser beam hardening is the treatment of plastic injection moulds. The desire for an ever increasing service lifetime demands a hardening of the edges of the tools. Typical tools, either in segmented or monolithic form, can weigh up to ten tons or more.
When in service, the high injection pressures (~ 1000 bar) can result in high wear on the entry and sealing faces, particularly if the plastic contains abrasive media. Wear of those regions results in parts with burrs on the edges, which often requires tedious removal by hand. Laser hardening is superior to flame or induction hardening since both of these techniques do not always produce the desired results and are limited in their application due to difficult geometries.