Machining of Metal Foams with Varying Mesostructure Using Wire EDM

Metal foams offer a wide range of applications including heat exchanger and light weight construction applications. The structure of these foams can be designed on different length scales using innovative technologies. Especially in the case of the mesostructure the relative density as well as the pore density can be varied in a relatively large scale [1], . Conventional machining of these materials is difficult due to their sensitivity to cutting forces. However, wire EDM has been proven to be an appropriate process for precise machining in this field [2]. In this study, the influence of the mesostructured parameters of aluminum metal foams on the EDM process is investigated. Herein the cutting rate is of particular interest. Furthermore the specific structure of metallic foams provides nearly ideal flushing conditions to the EDM process. Therefore, the influence of flushing on the EDM process is examined in this research. The results show that very fast feed speeds can be achieved due to the good flushing conditions and the low relative density of the material. Also a strong correlation of the relative density and the material removal rate was found.