Machinable zinc/aluminium alloy - suitable for automatic screw thread turning

摘要

Alloy comprises by wt. 20-35% A, 4-10% Cu, =0.2% Mg, bal. Zn and inevitable impurities. Alloy is prepd. by continuous or semicontinuous casting in the form of billets, the cast billet being cooled pref. by water to a certain temp. so that the core is not completely solid then allowing it to cool naturally, to eliminate the tendency to fissuring. The billet is then extruded into bar suitable for wire drawing, drawn and finely machined. Rates of casting, cooling etc. must be controlled within fine limits.