Precision electrodischarge machining of high silicon P/M aluminium alloys for electronic application

High silicon content aluminium alloys are preferred in electronic applications when low coefficient of thermal expansion and high thermal conductivity of material are require i.e. in housings for electronic packaging. This material is difficult to machine due to the large volume fraction of hard Si particles dispersed in relatively soft aluminium matrix. Electrodischarge machining (EDM) becomes very promising alternative to the traditional machining methods. In the present study aluminium alloys with 6-40% Si particles was manufactured by powder metallurgy (P/M) route. During EDM holes of 0,4mm diameter were drilled. After EDM the following parameters were determined: drilling speed V-d, surface roughness R-a, oversize of the hole drilled Delta. Above mentioned parameters were correlated with EDM parameters.