Ďuriška Libor, Černičková Ivona, Priputen Pavol, Palcut Marián
Faculty of Materials Science and Technology in Trnava, Institute of Materials Science, Slovak University of Technology in Bratislava, 917 24 Trnava, Slovakia.
Materials (Basel). 2021 Sep 19;14(18):5418. doi: 10.3390/ma14185418.
Complex metallic alloys (CMAs) are materials composed of structurally complex intermetallic phases (SCIPs). The SCIPs consist of large unit cells containing hundreds or even thousands of atoms. Well-defined atomic clusters are found in their structure, typically of icosahedral point group symmetry. In SCIPs, a long-range order is observed. Aluminum-based CMAs contain approximately 70 at.% Al. In this paper, the corrosion behavior of bulk Al-based CMAs is reviewed. The Al-TM alloys (TM = transition metal) have been sorted according to their chemical composition. The alloys tend to passivate because of high Al concentration. The Al-Cr alloys, for example, can form protective passive layers of considerable thickness in different electrolytes. In halide-containing solutions, however, the alloys are prone to pitting corrosion. The electrochemical activity of aluminum-transition metal SCIPs is primarily determined by electrode potential of the alloying element(s). Galvanic microcells form between different SCIPs which may further accelerate the localized corrosion attack. The electrochemical nobility of individual SCIPs increases with increasing concentration of noble elements. The SCIPs with electrochemically active elements tend to dissolve in contact with nobler particles. The SCIPs with noble metals are prone to selective de-alloying (de-aluminification) and their electrochemical activity may change over time as a result of de-alloying. The metal composition of the SCIPs has a primary influence on their corrosion properties. The structural complexity is secondary and becomes important when phases with similar chemical composition, but different crystal structure, come into close physical contact.
复杂金属合金（CMA）是由结构复杂的金属间相（SCIP）组成的材料。这些SCIP由包含数百甚至数千个原子的大晶胞组成。在其结构中发现了明确的原子簇，通常具有二十面体点群对称性。在SCIP中，观察到长程有序。铝基CMA含有约70原子百分比的铝。本文综述了块状铝基CMA的腐蚀行为。Al-TM合金（TM = 过渡金属）已根据其化学成分进行了分类。由于高铝浓度，这些合金倾向于钝化。例如，Al-Cr合金在不同电解质中可以形成相当厚度的保护性钝化层。然而，在含卤化物的溶液中，这些合金容易发生点蚀。铝-过渡金属SCIP的电化学活性主要由合金元素的电极电位决定。不同的SCIP之间会形成电偶微电池，这可能会进一步加速局部腐蚀攻击。单个SCIP的电化学惰性随着贵金属元素浓度的增加而增加。具有电化学活性元素的SCIP在与更惰性的颗粒接触时倾向于溶解。含有贵金属的SCIP容易发生选择性脱合金（脱铝），并且由于脱合金，其电化学活性可能随时间变化。SCIP的金属成分对其腐蚀性能有主要影响。结构复杂性是次要的，当具有相似化学成分但不同晶体结构的相紧密物理接触时，结构复杂性就变得重要了。
