| 摘要 |
PURPOSE:To reduce the fluctuation in the composition of a lead alloy of low antimony content in the melting and remelting of the alloy, by adding 0.02% or less by weight of copper likely to generate an intermetallic compound, to the lead alloy of 2% or less by weight in antimony content to make a base of the alloy. CONSTITUTION:Generally, the lower the antimony content of a lead alloy is, the larger the fluctuation of a eutectic region is. A region of such kind also fluctuates much, depending on the distribution of the composition of the alloy. Therefore, it is important to minimize the fluctuation in the composition of the molten lead alloy for casting, in enhancing the productivity of the casting. If the antimony content of the lead alloy is not higher than 2% by weight, the generation of dross is sharply fast in comparison with a conventional lead alloy. However, the addition of copper, which is not quite effective for a lead alloy of 3-5% by weight in antimony content, is effective to stabilize the composition of the lead alloy in the casting. For that reason, a positive electrode base is made of the lead alloy which has an antimony content of 2% or less in weight and to which 0.02% or less by weight of copper is added. |
