| 摘要 |
<p>An extrusion die has a die aperture which is negatively tapered essentially throughout its length at an angle (X) of at least 1° such that any friction stress between the die lands (20) and metal flowing through them is negligible, the length (C) of the lans (20) being not more than 2 mm so that fouling does not significantly take place thereon during extrusion. Faster extrusion speeds can be achieved, particularly when extruding aluminium alloy having a shear strength of from 1.2 to 4.0 Kg/mm2 at 500°C.</p> |
