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目前可采用的最高强度的变形铝合金是铝—锌—镁—铜系的这些合金在减轻飞机骨架重量方面具有很大的潜力。但是这些合金在使用中尚有一些现存的问题,断裂韧性和疲劳裂纹扩展抗力都低,对剥落腐蚀和应力腐蚀敏感。这些问题就导致了个别的飞机公司和许多国家政府收购者限制对它们的使用。这种情况又导致了英国和欧洲大陆广泛的采用铝—铜—镁—硅型的低强度合金,虽然在加工过程中蒙受很大的重量方面的害处。在美国一般较偏重于采用高强度铝—锌—镁—铜合金,在那里与其使用有关的一些问题由于在不长的时间内更换了成分而满意地得到了缓和。但是即使如此,在最近几年也出现了一种倾向,即利用这些合金在强度上稍低些的变化,来试图改进飞机框架的耐用性和可靠性。
The highest strength currently available for deformation aluminum is aluminum-zinc-magnesium-copper These alloys have great potential for reducing the weight of aircraft frames. However, there are some existing problems in the use of these alloys, the fracture toughness and fatigue crack growth resistance are low, the flaking corrosion and stress corrosion sensitive. These problems have led to the restrictions on their use by individual aircraft companies and many national government acquirers. This situation in turn led to the widespread use of low-strength aluminum-copper-magnesium-silicon alloys in the UK and continental Europe, albeit with significant weight-related disadvantages during processing. In the United States, the emphasis is generally placed on the use of high strength aluminum-zinc-magnesium-copper alloys where some of the problems associated with their use have been satisfactorily mitigated by the replacement of ingredients within a relatively short period of time. But even so, there has also been a tendency in recent years to take advantage of the somewhat lower intensity variations of these alloys in an attempt to improve the durability and reliability of aircraft frames.