Powder-metallurgical (P/M) produced components may be used as mass parts in a very large
quantity. Due to the multistage manufacturing process which consists of the pressing of the prepared
powder and the sintering of the green bodies also complex shaped components can be produced very
economically and precisely. They can be utilised without any further post-processing if the whole
production process is optimised. However, it is still difficult and only possible with considerable
technical and financial effort to produce highly stressable components profitably using the sinter
technique.
Therefore, the examinations on hand had the intention to create the basis for the use of the sinter
technology also for the production of highly stressable case-hardened components. To this, at first
bending specimens were fabricated with modern pressing procedures and sinter facilities and first
characterized in the as sintered state. Then the conditions for the case-hardening was analysed and the
parameters for an optimised case-hardening procedure fixed. With these parameters specimens were
case-hardened and their lifetime behaviour estimated under different bending loading conditions.
Finally it should be checked whether the knowledge gained from the specimens could be applied
to complex components. To this, gear wheels were produced using powder-metallurgy. The cyclical
tooth foot strength of this gear wheels were analysed in the only sintered as well as in the
case-hardened state. It could be demonstrated that the improvement of the fatigue strength of the
bending specimens by case-hardening also appears at the tooth foot strength of the gear wheels.
