金属间化合物Fe_3Al在氧中的常温延性比在空气中的高得多,且强度也有一定程度的增加,这证实了它在空气中的常温脆性是由环境造成的。添加适量的Cr可使合金的常温延性提高,但只有当材料表面形成氧化膜时,Cr的作用才较明显。XPS实验表明,这是由于在该氧化膜中有足够数量的保护性氧化物Al_2O_3,可以抑制或推迟Al和环境水汽的反应,使材料的本征韧性得以分充发挥。 The intermetallic compound Fe 3 Al has a much higher ductility at room temperature in oxygen than that in air and a certain increase in its strength, confirming that its ambient temperature brittleness in the air is caused by the environment. Adding proper amount of Cr can improve the ductility of the alloy at room temperature, but the role of Cr is obvious only when the oxide film is formed on the surface of the alloy. XPS experiments show that due to the sufficient amount of protective oxide Al 2 O 3 in the oxide film, the reaction of Al with the ambient water vapor can be suppressed or delayed, and the intrinsic toughness of the material can be fully charged.