一、前言 H62黄铜作为硬钎焊料具有很大的优越性,并得到广泛的应用。但是H62黄铜的熔点较高(905～910℃),生产上应用的钎焊温度高达1100℃,因此存在能耗大、污染严重、工件机械性能下降、容易变形等问题。上海自行车研究所与上海交通大学联合研制成的MC-81低熔点铜基焊料合金,是一种新颖的低熔点合金,它可以经济地在热态或冷态下加工成各种断面的钎焊料。它不含Sn、Ag、Ni等稀贵或紧缺的金属元素,资源丰富,成本低廉,且具备钎焊合金的各种优良性能。其熔点(818～838℃)比H62黄铜低得多,用于自行车工业的盐浴浸焊,其能源与焊料的节省颇为可观。同时,对某些工件,它可代替银焊中的焊料,在保护气氛中进行钎焊(例如矿用热风器散热片的焊 I. Introduction H62 brass has great advantages as a brazing material and has been widely used. However, the high melting point of H62 brass (905 ~ 910 ℃), the production of brazing temperature up to 1100 ℃, so there is energy consumption, serious pollution, mechanical properties of the workpiece decreased, easy to deformation and other issues. MC-81 low-melting-point copper-based solder alloy, jointly developed by Shanghai Bicycle Research Institute and Shanghai Jiaotong University, is a novel low-melting-point alloy that can be economically processed into various cross-section brazes under hot or cold conditions material. It does not contain Sn, Ag, Ni and other rare or scarce metal elements, rich in resources, low cost, and have a variety of brazing alloy excellent performance. Its melting point (818 ~ 838 ℃) is much lower than that of H62 brass. It is used in salt bath dip welding of the bicycle industry, and its energy and solder savings are considerable. At the same time, for some workpieces, it can replace the solder in silver soldering, brazing in a protective atmosphere (for example, welding of heat sinks for mine heat exchangers