| 摘要 |
<p>A wrought aluminium alloy product having the following chemical composition, expressed in wt%: - 1.3 % < Si < 12%, - 1.35 % < Fe < 1.8 % wherein the total Fe+Si content is higher than 3,4 %, preferably 3,6 %; - 0,15 % < Cu < 6 %; - 0.6 % < Mg < 3 %; - optionally, one or more of the following elements: - Mn < 1 %; - Cr < 0,25%; - Ni < 3 %; - Zn < 1 %; - Ti < 0.1 %; - Bi < 0.7 %; - In < 0.7 %; - Sn < 0.7 %; - other elements < 0.05% each and 0.15% in total; - and the balance aluminium. Preferably, this product is extruded from a billet which is homogenised at a temperature in the range of 525°C to 580°C for at least one hour. This product, which has excellent machinability and a very low roughness after hard anodisation treatment, may be used to obtain improved braking piston bodies.</p> |
