| 摘要 |
<p>The invented aluminium alloys with excellent machinability, particularly free-cutting materials based on aluminium-copper or aluminium-magnesium-silicon contain 0.2 to 1.2 percent by weight tin and Ú.2 to 1.0 percent by weight bismuth as a chip breaking additive. The aluminium-copper based alloy contains 4.8 to 6.0 percent by weight copper, 0.2 to 1.0 percent by weight bismuth, 0.2 to 0.7 percent by weight tin, at the most 0.45 percent by weight zinc, at the most 0.7 percent by weight iron, at the most 0.4 percent by weight silicon, as well as other accompanying elements in individual amounts at the most 0.05 percent by weight, total at the most 0.15 percent by weight and the balance being aluminium. The aluminium-magnesium-silicon based alloy contains 0.6 to 1.2 percent by weight magnesium, 0.5 to 1.2 percent by weight silicon, 0.6 to 1.2 percent by weight tin, 0.2 to 0.7 percent by weight bismuth, 0.2 to 0.6 percent by weight manganese, at the most 0.5 percent by weight iron, at the most 0.5 percent by weight, preferably 0.15 to 0.40 percent by weight copper, at the most 0.2 percent by weight, preferably 0.04 to 0.10 percent by weight titanium, as well as other accompanying elements in individual amounts at the most 0.05 percent by weight, total at the most 0.15 percent by weight and the balance being aluminium. Owing to a combined use of tin and bismuth, the addition of lead harmful to health can be omitted..</p> |
