How does laser hardening work?

Laser hardening is a technology for selectively advancing the mechanical properties of steels. On surfaces of a component that are subject to particular stress, the wear resistance can be increased with pinpoint accuracy, while the original properties are retained on the rest of the same workpiece.

The laser beam selectively heats the surface almost to the melting temperature, stimulating microstructural transformation. As the laser system moves the focal point (can also be designed as a line) further across the surface of the part, the heat is dissipated through the base material of the workpiece and quenching occurs "by itself.

The targeted use of laser energy thus makes it possible to treat small workpieces in a controlled manner with little heat input.

Depending on the material and process parameters, hardening depths from 0.1 to more than 2mm are possible. Laser hardening can be used in series production, but also for contract hardening shops and for a large variety of parts: in order to be able to cover a wide range of workpiece geometries, it is for example recommended, to install the laser optics on a 6-axis industrial robot.

What are the advantages of laser hardening?

• Limiting the Hardening process to specific areas
  
• Low distortion
• Contactless
• Short process times
  
• Quenching process is not necessary
  
• Energy-efficient

Precision

Pinpoint hardening by laser also requires appropriate mechanical engineering: in order to follow the contour and workpiece geometry precisely, the mechanical design of the laser system must enable the corresponding precision.

This requires a robust design with high-quality components and optimally set-up linear and rotary axes.

In addition, automation also means that the workpieces are automatically fed, moved and fixed. Here, attention must be paid to clamping with low deviations/tolerances so that the laser hardening process can be carried out in a repeatable and process-reliable manner.

Selection of components

Which laser type (e.g. diode laser) and which laser power must be selected for the laser hardening process? Which laser optics must be used to obtain the desired results with the laser spot? What needs to be considered in terms of laser safety and extraction?

These and many other questions may arise when you first come into contact with the laser hardening process - the decisive factor is the right contact person, who will clarify the questions point by point together with you and thus put together the right solution for you. Laser hardening systems cannot be bought "off the shelf", as the specific requirements always depend on the specific application.

Layout example laser hardening system for bending dies

With Wieser laser hardening systems, precise and contour-accurate hardening is possible with efficient energy consumption at the same time: the customized design combines state-of-the-art laser technology with robust mechanical engineering and future-oriented connectivity options –designed from scratch according to your individual requirements.

• Laser hardening optics on fully automatic CNC 4-axis system (robust XYZ-frame with additional swiveling axis)
• Exchanging table shuttle system: while the hardening process is executed on the workpieces of the first shuttle in the system, the second shuttle can be loaded and unloaded at the same time.
• Two shuttles with 2.000 x 500mm workpiece support tables
• Automatic machine door and integrated extraction system
• Complete data connection system according to Industry 4.0 standards
• User interface adapted for ease of operation
• Eligible investment
• Prepared for fully automatic robot loading