应变速率对LC4CS铝合金腐蚀性能的影响

Effect of Strain Rate on Corrosion Features of LC4CS Aluminum Alloy

在腐蚀环境和外力的协同作用下 ,铝合金的某些电化学性能将发生明显变化。本文发现 ,随着应变速率的增加 ,LC4 CS铝合金自腐蚀电位负移的速率也增加。当与阳极氧化后的铝合金耦合时 ,LC4 CS铝合金的耦合电流随应变速率的增加而逐渐增大 ,应变量大于 0 .0 4后的耦合电流急剧增大。在小幅度恒电位方波的作用下 ,暂态电流呈现新奇的力学效应。可以认为暂态电流的波动 ,将预示着铝合金表面状态的变化。尽管暂态电流波形受自腐蚀电位负移的影响而不对称 ,无法从恒电位的负向极化准确测量暂态电流 ,但是 。

Under the synergistic action of environmental and mechanical factors, the corrosion features of aluminum alloys are evidently change. It is discovered that the negative drift rate of natural corrosion potential is increased with the strain rate. In the state of galvanic couple with the aluminum alloy anodized, the larger the strain rate is, the larger the couple current is. And while strain is equal to 0.04 about, the couple current will sharply spread. Under the potentiostatic polarization of small amplitude square wave, the transient current of the aluminum alloy shows novel mechanical effect. The fluctuation of the transient current indicates the variation of surface properties of aluminum alloy. Despite of influence of negative drift of natural corrosion potential on transient current waveform, and the precise measure of transient current from negative polarization is impossible, the polarizational results are consonant with the experimental data in the couple action.