中温轧制对Al-Cu-Mg-Ag耐热铝合金组织与抗腐蚀性能的影响

通过晶间腐蚀和剥落腐蚀性能测试,对经过不同中温轧制变形的Al-Cu-Mg-Ag合金的抗腐蚀性能进行研究,并通过金相分析和透射电子显微分析等对其机理进行探讨。结果表明,采用合适的中温轧制变形后,合金的抗腐蚀性能在不同程度上得到提高。随着变形量的增加,晶内析出相发生变形并向晶界移动,导致晶间无沉淀析出带变窄,合金的腐蚀通道变窄,抗晶间腐蚀性能得到提高。另一方面,沿着轧向变长的晶粒会降低合金的剥落腐蚀性能,导致变形量较小时(10%~50%)合金的抗腐蚀性能得到提高,而较大的变形量(80%)会降低合金的抗剥落腐蚀性能。

Effects of rolling at intermediate temperature on the microstructure and corrosion resistance of Al-Cu-Mg-Ag heat-resistance Al alloy

The corrosion resistance of Al-Cu-Mg-Ag alloy was studied by intergranular corrosion test and exfoliation corrosion test. The mechanism was discussed by metallographic analysis and transmission electron microscopy. The results show that,the corrosion resistance of the alloy can be enhanced by appropriate rolling deformation. With increasing the deformation amount,the strengthening phases deform and move to the grain boundaries,which leads to a narrower precipitation free zone (PFZ). The corrosion channel narrows and the corrosion resistance of the alloy increase. On the other hand,the elongaged grains along the rolling direction can decrease the exfoliation resistance of the alloy. As a result,the corrosion resistance of the alloy with a relative smaller deformation amount (10~50%) is increased,and that of the alloy with a larger deformation amount (80%) is decreased.