Development of Lead-Free Copper alloy Manufacturing System Based on Life Cycle Assessment

采用复合分离法研究了含铅青铜中除铅的方法。将NaF加入到熔融青铜中，然后加入Ca-Si化合物。因此，促进了ca与Pb的反应，而没有促进ca与Sn的反应。该方法可使含铅5.5质量%的青铜中Pb的去除率达到82%。对原使用原始材料的无铅铜合金制造系统和利用生产过程中去除含铅铜合金废料的新系统进行了库存分析。结果表明，从旧的制造系统向新的制造系统转变，显著降低了全球变暖、酸化、能源消耗和资源消耗等环境影响。因此，从LCA的角度来看，使用回收铜合金废料的新制造系统优于使用原始材料的旧制造系统。研究了二硫化钼对青铜可加工性的影响。结果表明，加入二硫化钼可大大提高切削力和切屑的可加工性。

The method for removing Pb from bronze containing Pb was examined by the compound-separation method. NaF is added to molten bronze, followed by adding the Ca-Si compound. Therefore, the reaction of ca with Pb is promoted without the reaction of Ca with Sn. Using this method, 82% of Pb can be removed from bronze containing 5.5 mass% Pb.The inventory analysis of both the former Pb-free copper alloy manufacturing system that uses virgin materials and the new one that uses copper alloy scrap containing Pb, which is removed in the production process, was carried out. The results show that the shift from the former manufacturing system to the new one reduces environmental impacts such as global warming, acidification, energy consumption and resource consumption significantly. Thus in the LCA perspective, the new manufacturing system that uses a recycled copper alloy scrap is superior to the former one that uses virgin materials.The effect of molybdenum disulfide on machinability of bronze was examined. The result shows the cutting forces and chip-disposability can be greatly improved by the addition of molybdenum disulfide.