| 摘要 |
<p>Tin alloy contg. by wt. 0.1-7.0% Sb, 0.1-8.0% Cu, 0.5% max. Pb, 4% max. Ag. To improve workability in the mfr. of tinware or pewter, the alloy also contains 0.0045-0.45%, esp. 0.015-0.05% Zn, 0.0005-0.05%, esp. 0.001-0.005% Al, and 0.0001-0.01% esp. 0.0005-0.0025% Mg, the balance being tin. The tin alloy(a) contg. the Sb, Cu, Pb and Ag is pref. melted, and then 0.005-0.5% esp. 0.02-0.1% of a Zn-Al-Mg alloy(b) added. Alloy(b) pref. contains 0.5-10% Al, 0.1-8% Mg, balance fine zinc; and the esp. pref. compsn. of alloy(b) is 4.8-5.2% Al, 2.5-4% Mg, rest Zn. In the mfr. of pewter, the normal alloy(a) meets DIN 17810, but defects can arise such as microcracks or fissures in deep-drawing, flow-forming and other working operations. The addn. of Zn, Al and Mg prevent the segregation of the Cu6Sn5 phase, so a fine structure is obtd. in which the Cu6Sn5 consists of small spheroids instead of coarse needles. The coarse structure normally obtd. impairs workability and results in an uneven atack when pewter articles are pickled.</p> |
