Laser structuring

Sublime microprofiles cause increased stiction

Microprofiles FOR high static friction

Laser structuring is increasingly used for roughening of surfaces. Superior micro profiles are created with thies process, which cause the highest possible static friction to the counter body. The pulsed laser beam is focused on one point of the material surface whereby very high local intensities occur. Through the thermal machining process the material is turned temporarily into a liquid phase. This leads to warpings which stand out of the surface.

The single profile peaks consist of melt fins which couple with its superior surface structures in its function as component in the surface of the counter body and create a high static friction.

Principles of laser structuring

A connecting rod bearing consists of the large connecting rod eye, the bearing shell and the crank pin of the crankshaft. Whereas the friction between the crank pin and the interior of the bearing shell is minimized, it must be maximized for the torsional reliability on the exterior. A frictional connection is therefore required between the connecting rod eye and bearing shell. After the precision machining (e.g. honing or precision boring) of the connecting rod eye the machined surface is structured with a solid state laser. The torsional reliability of the mounted bearings to be achieved is thus the deciding quality parameter of laser structuring.

Plants of Laser structuring

For industrialization of laser structuring plants are developed, which work with higher process reliability in modern production lines. As sound source Q-switched laser with galvo scanner optic are used, which are normally found in labelling and marking of surfaces applications.
For reduction of cycle time also more sound sources can be arranged. The arrangement occurs depending on the machining task. During structuring of bore sections the rays fall diagonal in the bore. During processing of direct accessible surfaces the beam control can occur normal to machining surface.

Objective of laser structuring

Through roughening of technical surfaces with static friction function a loss-free twist and/or restrained joint between two components is created.
This connection fulfills the functional requirements and simplifies the constructive layout of the components.
Moreover, friction increasing intermediate materials as for example diamond foils are substituted and the costs of manufacture are further reduced.