| High Si-Al alloys is used as a new electronic packaging materials because of itshigh thermal conductivity, low coefficient of expansion and low density. High Si-Al hasshown a great application prospect. High ratio of silicon in the Si-Al alloys causes highbrittleness of the material, which leads to poor mechanical processability of the materialand serious tool wear. However, electrical discharge machining (EDM) showssignificant advantage in processing thin-wall, micro beam and tiny holes. Because nomacroscopic force arises during the processing. Therefore, study on EDM processing ofsilumin means a lot to the development and applications of materials.By single factor experiment and orthogonal experiments, effect of variousparameters on the process performance was studied, EDM process regularity for highsilicon aluminum alloy material was summarized,and combination of different processparameters for different process requirement was gained. Comparative analysis of thedifferences in the processing performance of casting and spray deposition wasconducted, which provided reference processing data for the materials’ application.The influence of the polarity effect, processing area and power mode on theprocess performance were investigated by prcossing injection-shaped silumin in bothEDM and Powder-Mixed EDM (PMEDM). Difference between the two processingmethods was analyzed. The results showed that positive polarity machining, largerprocessing area and constant frequency pulse could greatly promote the surface quality.The effect of the EDM and PMEDM on surface element, surface corrosionresistance, surface microhardness, surface and abrasion resistance was analyzed.Experiment results shows that EDM greatly improved the surface corrosion resistanceability, surface microhardness, surface abrasion resistance ability and PMEDM tendedto be better.The results proved that the EDM had the potential in machining the material ofhigh Si-Al alloys for electronic packaging. |
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