Cutting aluminum wears the power feed contact and quickly forms a deep groove on the power feed contact, and this deep groove is very easy to break the feeding molybdenum wire, and the molybdenum wire can't be pulled out when it got stuck in the groove.
The reason is that when cutting the aluminum, a large amount of alumina or particles with alumina adhered to the surface of the wire. The surface is getting extremely hard and has abrasive properties.
This adhered alumina level acts as an abrasive tool grind contact position between the molybdenum wire and the power feed contact. Then deep groove formed, soft aluminum and hard abrasive grains are mixed and stuffed in the groove. Then the molybdenum wire is easy got stuck to break. Another reason that the power feed contact quickly forms a deep groove is that the aluminum oxide is between the molybdenum wire and the power feed contact so that when the two are in motion, they are insulated to form a spark discharge, and the discharge makes the conductive block etch faster. Unlike the CNC EDM wire cut machine, this is a common disadvantage of reusable wire cutting EDM machines that rely on power feed contact for picking up the high-frequency power.
It is not just for cutting aluminum, similar phenomenon happens when cutting conductive ceramics, silicon nitride, and boron nitride.
1) Order the machine with an aluminum cutting device
2) Use special brass wire for cutting aluminum