Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Processing of an over-eutectical wear-resistant steel by powder metallurgy



Datum: 30.05.1990


Author


Reporter

  • Prof. Dr.-Ing. M. Geiger
  • Prof. Dr. Mughrabi

Within mass production of mouldings by powder metallurgy the material costs are an important factor concerning the total product costs. In the scope of this work, a low cost material was chosen to be manufactured by systematically optimizing the manufacturing processes, thus the resulting microstructure meets the technological requirements. These properties comprise the tensile as well as the compressive strength, the wear resistance and the process accuracy. For the investigations a powder metallurgical production line was developed allowing for varying specimen geometry, among those automotive camshaft elements. Different test stands were developed for the wear resistance tests, enabling to shorten the total testing time by means of a testing chain at 99 per cent with respect to conventional component tests. Adapting the density of the specimen, the temperature-time profile and the sintering atmosphere to the properties of the over-eutectical steel, the theoretical density is reached by high-temperature sintering within just 20 minutes sintering time, providing homogeneous microstructure at the same time. This microstructure leads to the mechanical requirements of the component. The compressive strength succeeds 2.4 GPa. The wear resistance within camshaft element testing is improved in comparison to near-surface remelt iron.