氟铝酸铯铝钎剂制备和活性成分的研究

Preparation and Active Ingredient Study of CsF-AlF3 System Aluminum Flux

以CsF和AlF3·3H2O作为原材料,采用化学法、烧结法和水合法3种不同的制备方法进行铝钎剂的制备。通过DSC-TGA试验、XRD衍射法分别分析焊剂的熔化特性和物相组成;采用CsF-AlF3焊剂进行铜铝异种金属的钎焊,进行了接头的剪切强度测试和焊缝显微组织观察。结果表明：3种制备方法中,化学法中的氢氟酸使CsF和AlF3之间的反应较为充分,形成了CsAlF4、CsAlF4·2H2O和Cs2AlF5·H2O物相,而烧结法和水合法制备的钎剂无CsAlF4物相。CsAlF4物相作为钎剂的活性成分有助于提高助焊效率,在焊接过程中形成了较厚的金属间化合物层,为焊接接头提供了良好的冶金结合,从而提高了接头的剪切强度。

The aluminum flux was prepared by three different methods of chemical reaction method,sintering method and water hydration with CsF and AlF3·3H2O as the raw materials.The melting characteristics and phase composition of the fluxes were measured by DSC-TGA test and X-ray diffraction method,respectively.The Al/Cu joints were brazed with the CsF-AlF3fluxes,and the shear strength test and microstructure observation of the Al/Cu joints were carried out.The results show that compared with that by the sintering method and water hydration,hydrofluoric acid of chemical reaction method makes CsF and Al3F react more adequate and forms CsAlF4,Cs Al F4·2H2O and Cs2AlF5·H2O phases.However,the fluxes prepared by sintering and hydration process don＇t have Cs Al F4phase.The CsAlF4phase as the active ingredient of the flux is helpful to improve the welding efficiency and it forms a thick intermetallic layer,which leads to good metallurgical bonding for welded joints,thus improving the shear strength of the joints.