Hot Forging of partially particle-reinforced sintered components

• Applicant: Professor Dr.-Ing. Bernd-Arno Behrens
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 283970253

The range of applications for light metal components (magnesium, aluminum or titanium) is subject to con-tinuous expansion so that steel components will be substituted by light metal parts. However, being ex-posed to high tribological, mechanical and thermal stress, magnesium and aluminum components reach their technical limits. Consequently, metal-matrix composites (MMC) combining the positive characteristics of a light metal (low weight, high ductility) and a reinforcement phase (high hardness, high strength, good wear resistance). Most of MMC components are produced with a homogeneous distributed particle density within the material, so that a relative high percentage of the cost-intensive reinforcing phase must be used. Although only some areas of the part are exposed to the stress. By producing partial reinforced parts, the proportion of the reinforcing phase can be reduced and parts, specially tailored to the stress profile, can be produced. The aim of this research project is to examine the specific-forming behavior and mechanical material proper-ties of partially particle-reinforced powder parts. For this reason, rotational symmetric raw parts, consisting of a base material (aluminum powder) and a MMC (aluminum powder + ceramic powder) with a concentric layer structure will be formed by powder pressing and subsequently heat treated by sintering. The produced sintered parts are the raw material for the subsequent forging operation, in which the existing residual porosity will be reduced. The effects of the different forming parameters (forming temperature, forming speed, deformation rate) on the material flow of the partially particle-reinforced material system and the material properties will be analyzed. On the basis of the different examined material parameters, numerical simulations will be carried out in order to analyze the evolution of the pores during the forming process. By this means the influence of the porosity on the deformation behavior of the used material can be determined. Compared to most existing studies for manufacturing partial particle-reinforced powder components or gra-dient materials, this research project is focused on powder systems with concentric (radial) layer arrange-ment. This can result in interesting scientific questions for both the semi-finished products as well as for the subsequent forging of the semi-finished products regarding to their material flow and compaction properties.

• DFG Programme: Research Grants