合金相对新型铝锂合金局部腐蚀行为的影响研究进展

Review on Effect of Alloy Phases on Localized Corrosion of New Generation Aluminum-Lithium Alloys

新型铝锂合金具有低密度、高弹性模量以及高比强度和高比刚度等优点,在航空、航天等领域应用前景广阔。综述表明含Cu、Li元素高的第二相颗粒对铝锂合金局部腐蚀行为影响最大,此外通过塑性变形并不能有效消除第二相颗粒对合金耐蚀性的影响,因此如何消除或减轻这种影响尚待研究;时效前预变形可促进铝锂合金中T_1(Al_2CuLi)相析出并细化T_1相尺寸,但对θ'(Al_2Cu)和δ'(Al_3Li)相则存在抑制作用;当合金发生不均匀塑形变形时,T_1相的分布将随晶粒取向而发生变化,导致晶粒尺度上的局部腐蚀。

The new-type aluminum lithium alloys have been increasingly used in aerospace industry due to their low density, high elastic modulus and high specific strength and stiffness. The effect of alloy phases on localized corrosion of the new generation aluminum-lithium alloys has been reviewed.It is concluded that the constituent particles containing high concentrations of copper and lithium have the most significant effect on corrosion resistance of A1-Li alloys, and that plastic deformation could not effectively remove such influence. Therefore, the way to eliminate or alleviate such effect is still awaited. Additionally, the per-deformation before artificial aging could promote the precipitation of T1 （AI2CuLi） phase and reduce its size at the same time, but restrain the precipitation of 0＇（A12Cu） and 8＇ （A13Li） phases. Further, the distribution of TZ phase will depend on the grain orientation when plastic deformation occurs unevenly within different grains, which results in localized corrosion at the grain scale in A1-Li alloys.