Reduction of wear at hot forging dies by using coating systems containing boron

verfasst von
Bernd Arno Behrens, Günter Bräuer, Hanno Paschke, Marcus Bistron
Abstract

The near surface area of forging dies is exposed to high mechanical loads. Additionally thermal and chemical stresses appear during the hot forging process. Depending on the number of forged parts, several kinds of stresses occur in the near surface area, which lead to the initial failures of forging dies. Wear is the main reason for production downtimes with a ratio of 70%. Furthermore, thermal and mechanical cracks are typical causes for failures causes as well as plastic deformation. In order to reduce wear, the abrasion resistance of the forging die surface has to be increased. Hence, different methods like plasma nitriding and optional additional thin hard coatings (TiN, TiCN, TiC, TiBN and TiB2) were successfully examined. Recently developed Ti-B-N coatings in specific multilayer designs are thermally stable, wear-resistant and anti-adhesive regarding the sticking of work piece material. This paper presents the wear reduction possibilities of boron-containing multilayer coating systems applied to forging dies by using the plasma enhanced chemical vapor deposition treatment. A basic mechanical and analytical characterization of different coating systems is realized in the first stage of the project. Best qualified multilayer coating variants were applied to forging dies for experimental investigations. As a result of the tests, wear can be reduced significantly by using thermally stable boron multilayer coatings. To receive realistic wear values under production conditions, an automated forging process was used for testing. After 3,000 forged parts, the coatings were examined by tactile measurement, SEM and EDX analyses to characterize the occurring wear.

Organisationseinheit(en)
Institut für Umformtechnik und Umformmaschinen
Externe Organisation(en)
Fraunhofer-Institut für Schicht- und Oberflächentechnik (IST)
Typ
Artikel
Journal
Production Engineering
Band
5
Seiten
497-506
Anzahl der Seiten
10
ISSN
0944-6524
Publikationsdatum
20.03.2011
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Maschinenbau, Wirtschaftsingenieurwesen und Fertigungstechnik
Elektronische Version(en)
https://doi.org/10.1007/s11740-011-0308-z (Zugang: Unbekannt)
 

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