Ceramic-steel bonds for adhesion reduction in aluminum forging

Theme	Forming technology
Project title	Ceramic-steel bonds for adhesion reduction in aluminum forging (ALDi)
Project duration	01.07.2009 – 30.06.2011

In hot forming of aluminum the die surfaces are subject to adhesive wear due to the high affinity between aluminum and steel materials. Particularly in forging operations, where high normal stresses and forming temperatures occur, this kind of die wear leads to premature failure of the tool. The aim of the project is to expand the knowledge of the die failure mechanisms in hot forging of aluminum. Furthermore, a coating concept will be tested by a systematic study of forming tools dispersed with ceramic particles, which reduces the adhesion tendency of the material combination of steel and aluminum and increases tool life. Suitable ceramic materials are introduced into selected surface areas of the tool by laser dispersing. Using these metal-ceramic composite layers basic studies are conducted to characterize the properties, particularly with regard to adhesion of the aluminum. The results of those studies allow an increase in tool life of aluminium forging tools.

Publications about the project

Forming technology, Tool- and Mold-Making Lücke, M.: Werkzeugverschleiß in der Aluminiummassivumformung. In: Behrens, B.-A.; Nyhuis, P.; Overmeyer, L. (Hrsg.): Berichte aus dem IPH, Band 4/2018, TEWISS – Technik und Wissen GmbH, Garbsen 2018. ISBN: 978-3-95900-239-4.

When forging aluminum, the main cause of tool failure is adhesion-related wear. The high affinity for the adhesion of aluminum alloys to the steel materials of the forging dies results in so-called "stickers", which have a negative influence on the forging result. As a result, the engravings on the tools must be regularly overhauled. The overhaul interval depends largely on the workpiece geometry and temperature as well as on the tool temperature, material and surface.

This paper develops a model that predicts the adhesive wear and thus determines the tool life or the time of potential tool failure. This model is based on the correlation of simulative and experimental data. After evaluating the sensitivity of the varied parameters, influencing variables such as forming or die temperature are combined in a data mining model. With the help of various algorithms, the surface quality and therefore the tool life can be predicted after simulation of any aluminum forming process.

forging, adhesion, aluminum, wear

www.tewiss-verlag.de

Forming technology Behrens, B.-A.; Müller, K.; Lücke, M.: Keramik-Stahl-Werkstoffverbundschichten als Adhäsionsschutz in der Aluminiumumformung. In: wt Werkstattstechnik online, Springer VDI-Verlag, 100. Jg. (2010), H. 3, S. 207-210.

In a current research project at IPH – Institut für Integrierte Produktion Hannover gGmbH and Laser Zentrum Hannover e. V. the knowledge of die failure mechanisms during the forming of aluminium will be extended. Aspects of the analysis are minimization, quantification and forecasting of adhesion. Furthermore it will be analysed in what way the tools, laser-dispersed with aluminium oxide, decrease the adhesion.

aluminium forging, wear, wear coatings

Tool- and Mold-Making, Forming technology Lücke, M.; Krause, A.; Nickel, R.: Für Schmiedewerkzeuge wird der Verschleißschutz immer wichtiger. In: MM MaschinenMarkt, Vogel-Buchverlag, o. Jg. (2010), H. 12, S. 42-44.

Quality requirments are demanding wear protection for forging dies to ensure a long life time in combination with dimensional accuracy. This paper describes the investigation of yet unknown coatings in the forging industry like laser based hard coatings and diamond like carbon coatings.