Titanium and Zircaloy-4 dissimilar alloys were brazed with a zirconium-titanium-copper-nickel amorphous filler alloy, and the resulting joint structures as well as their corrosion properties were examined. The microstructure of the brazed joints was investigated according to brazing holding time at 850 °C, and the corrosion property was analyzed by potentiodynamic polarization. During brazing, joints were produced by diffusion-induced isothermal solidification of the molten filler alloy. At a relatively brief brazing holding time of 5 min, a large segregation zone consisting of an active α-phase and a nobler intermetallic phase was generated in the joint center, which suffered from micro-galvanic corrosion. The presence of alloyed titanium deteriorated the nobility of the α-zirconium phase near the joint and induced galvanic coupling with cathodic base metals, resulting in massive localized corrosion. This localized corrosion caused the pitting behavior at the applied potential of −51.1~187.5 mV during anodic polarization. With a brazing holding time of 20 min, the concentration of the alloying elements was homogenized to eliminate the electrochemical potential difference and minimize the galvanic corrosion susceptibility of the joint region. This homogeneous joint resulted in a highly passive corrosion behavior comparable to that of the titanium base metal.

中文翻译：

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用Zr-Ti-Cu-Ni非晶填充合金钎焊的Ti-to-Zr异种合金接头的组织和腐蚀性能

将钛和Zircaloy-4异种合金与锆-钛-铜-镍无定形钎料钎焊，并检查了所得接头结构及其腐蚀性能。根据在850°C下的钎焊保持时间，研究了钎焊接头的微观结构，并通过电位动力学极化分析了腐蚀性能。在钎焊期间，通过扩散诱导的熔融填充合金的等温凝固来产生接头。在5分钟的相对较短的钎焊保持时间下，在接头中心产生了一个由活性α相和一个贵金属间相组成的大偏析区，该偏析区遭受了微电流腐蚀。钛合金的存在会降低接头附近的α-锆相的贵金属，并引起与阴极贱金属的电偶合，从而导致大量局部腐蚀。这种局部腐蚀在阳极极化期间在-51.1〜187.5 mV的施加电势下引起点蚀行为。在20分钟的钎焊保持时间下，合金元素的浓度被均匀化，以消除电化学电势差并使接合区域的电化腐蚀敏感性最小化。这种均质的接头产生了与钛基金属相当的高度被动腐蚀行为。在20分钟的钎焊保持时间下，合金元素的浓度被均匀化，以消除电化学电势差并使接合区域的电化腐蚀敏感性最小化。这种均质的接头产生了与钛基金属相当的高度被动腐蚀行为。在20分钟的钎焊保持时间下，合金元素的浓度被均匀化，以消除电化学电势差并使接合区域的电化腐蚀敏感性最小化。这种均质的接头产生了与钛基金属相当的高度被动腐蚀行为。