Abstract
Recently, high quality bar and wire for office automation and automobile industries are required higher surface roughness, lower cost production. In order to produce ultra-smoothing bars by only drawing process, a new die was developed and evaluated. In conventional process, the surface of drawn bar and wire was smoothed by the additional processes such as grinding and polishing. However, these processes brought higher production cost and lower productivity. The new die had protrusion between bearing length. The protrusion die induces high contact pressure and shearing strain at surface of drawn bar. As a result, the surface roughness of Al-Si alloy extruded bar was achieved under 1 n m by the new method.
