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一、绪言到目前为止铝仍然是重量轻、加工性好和经过时效硬化能提高强度的优良金属材料.尤其是经过阳极氧化等表面处理后,不但提高了抗蚀性能而且表面也变得美观了,这种特有的优点在其他金属上是罕见的.然而对于焊接问题,特别是钎焊技术,虽然已作过探讨,但是究竟使用何种方法好,现在尚不明确.这是由于铝和其他金属(如铜、铁和镍等)材料相比,其焊接性能明显较低的缘故.因焊接性能低而严重地妨碍了铝的工业应用.其主要原因是由于铝表面存在着致密而坚硬的氧化膜所致.一些金属形成氧化物时的自由能值示于表1.从该表可明显地看出铝的自由能值很小,容易形成氧化物.依靠还原或分解作用进行氧化,就形成难以分解的、稳定的氧化物,该氧化物影响钎焊.
I. INTRODUCTION Aluminum has so far been an excellent metal material that is light-weight, good machinability and strength-enhanced after age hardening, especially after anodizing and other surface treatment, not only improves the corrosion resistance but also the surface is beautiful , This unique advantage is rare on other metals, however, soldering issues, especially brazing technology, have been explored, but it is unclear exactly which method to use, which is not clear at this time due to the combination of aluminum and other Metal (such as copper, iron and nickel, etc.), the welding performance is significantly lower due to low welding performance and seriously hindered the industrial application of aluminum.Its main reason is due to the existence of dense and hard aluminum surface Oxide film due to the formation of oxides of some metals, the free energy value is shown in Table 1. It is clear from the table that the free energy of aluminum is very small, easy to form oxides. Depended on the role of reduction or decomposition of oxidation The formation of hard-to-decompose, stable oxides that affect brazing.