Influence on the microstructure of powder metallurgical metal foam by means of mechanical alloying
Due to the process, metal foams produced by powder metallurgy have an inhomogeneous pore structure. Typical are pore size variations between a few tenths of a millimeter up to the centimeter range. This leads to unsteady properties and makes the predictability of metal foam based components difficult.
The present work deals with the approach to precondition the feedstock powder for the production of metal foams by mechanical alloying. Thereby, the homogeneous distribution of the blowing agent TiH2 is already present in the so-called composite powder. In addition, there is the possibility to add reinforcement particles with regard to a further improvement of the mechanical properties. Overall, this leads to a rather wide range of possible influencing factors and parameters to be varied. Accordingly, the present work is only a preview of a broad experimental program, taking into account the design of experiments and is currently being processed.
In this first study we've used the alloy AA6060 as matrix material. The evaluated method provides a finer pore structure associated with a modified foaming behavior.