LaserPromise

Laser-based deposition of adhesion promoter layers:

The LaserPROMISE project (laser-based deposition of adhesion-promoting coatings on stainless steels) is concerned with the research and validation of a process for the ageing-stable bonding of stainless steels specifically in the field of medical technology as part of the funding measure "The Basis of Photonics: Functional Surfaces and Coatings" of the German Federal Ministry of Education and Research. Adhesive bonding is currently not used for these applications due to the frequent sterilization treatments of medical instruments, as aging of the adhesive layer sets in and it fails prematurely as a result.

Research into a highly spatially resolved pretreatment process for ageing-stable bonding of stainless steels:

Current pretreatment methods for stainless steels (e.g. sandblasting with silicate-coated corundum or wet-chemical pickling) are not sufficiently stable to aging and are only suitable to a limited extent, particularly for medical applications, because the lack of local dissolution leads to pretreated areas which are not covered with adhesive and corrosion resistance is significantly reduced at these points. There is also the problem that, due to a lack of specialist knowledge, adhesive bonding technology is often not used for stainless steels, even though it would be the more suitable joining process compared with traditional joining methods (e.g. welding). Welding of stainless steel is only possible to a limited extent and often at great expense. Adhesive bonding would represent a real alternative here for many products.

The aim of the project is to research and evaluate both economically and technically a pretreatment process to bond stainless steels in an aging-stable and reliable manner, particularly with regard to the special requirements of medical technology. To achieve this goal, the mechanisms that lead to the failure of bonded joints of stainless steels must first be investigated.
These findings form the basis for designing the adhesives and the adhesion promoter layers. The laser systems used for cleaning are modified to enable deposition of adhesion promoter layers. The intended process is not only widely used in medical technology. The combined cleaning by means of laser radiation and the simultaneous deposition of adhesion promoter layers in combination with corrosion reduction suggests broad application potential. Further conceivable applications can be found in bonding in the automotive sector and in pump construction. All applications in which bondings are exposed to corrosive media or high corrosive stresses, the targeted process can offer significant potential. It should also be mentioned that there are virtually no limits to the combination of adhesion promoter layers and adhesives in terms of specific formulations, so that case-specific and optimum solutions can be developed for almost any application that currently requires conventional pretreatment. The technological basis for these developments will be developed with the research results of this joint project.