aluminum cutting not only wastes conductive blocks, but also quickly forms a deep groove, and this deep groove is very easy to pinch off the wire, so that molybdenum wire caught in the groove can't be pulled out. The reason is that when cutting aluminum, a large number of alumina or particles with alumina on the surface will be produced, and their surfaces are extremely hard and have abrasive properties. As an abrasive, deep grooves will soon be ground at the contact parts between molybdenum wires and conductive blocks, and soft aluminum and hard abrasive particles will be mixed together and filled in the grooves. Once they are brought in, the grooves will be squeezed to death and the wires will be broken. Another reason why the conductive block quickly forms a deep groove is that alumina is between the molybdenum wire and the conductive block, so that the two are insulated when they are in motion and form a spark discharge, and the discharge makes the conductive block erode faster. This is a disadvantage of the fast-moving wire cutting machine that relies on conductive blocks to feed electricity.
The phenomenon is similar when cutting aluminum, conductive ceramics, silicon nitride and boron nitride.
Using denser material as the conductive block, adding rubber scraper between the conductive block and the guide wheel, using cleaner coolant, frequently changing the working position of the conductive block, and using wide intervals of small veins to reduce the anti-sticking of the wire, seems to be effective, but it is not obvious. The fundamental solution is to change the shaft to enter electricity. However, the shaft feeding will produce a new contradiction between the structure and the large resistance of the wire path.
fortunately, the product rate of aluminum cutting is always less than that of steel cutting, and it is still desirable to adopt the machine tool structure with conductive blocks for simple manufacture and operation. It is adopted by most machine tool manufacturers.