外力对常温氧化膜开裂和剥落行为的影响

对外力下常温氧化膜开裂和剥落行为的影响作出了研究.从理论上推导出计算氧化膜临界开裂外力的公式,并通过A3钢发蓝膜和LY12CZ铝合金化学转化膜在扫描电镜下的动态拉伸实验证明氧化膜临界开裂外力的存在,同时还比较了两种不同氧化膜开裂行为的异同.另外,进行了氧化膜在3%NaCl溶液中开裂和剥落行为的电化学研究,通过两种材料在介质中拉伸时的自腐蚀电位变化情况,根据电位转折点的存在进一步验证了临界开裂外力的存在,最后进行了有无裂纹氧化膜的阻抗谱测量,说明氧化膜开裂将会加速电化学腐蚀.

Influence of applied stress on cracking and apalling of oxide film in room temperature

The cracking and spalling behavior of the oxide film under applied stress in room temperature was studied.The critical applied stress of oxide film cracking and spalling was calculated.By dynamic tension experiments of oxide film on A3 steel and LY12CZ aluminium alloy,the existence of critical applied stress of oxide film cracking and spalling was proved.The different cracking and spalling behavior of two kinds of oxide film was also compared.The electrochemical behavior of oxide film cracking and spalling in 3%NaCl solution was studied,according to the variety of open circuit potential of two kinds of materials under applied stress.The sharp drop in the open circuit potential proved the existence of applied stress too.Finally electrochemical impedance spectroscopy(EIS) measurement of oxide film with and without cracks was carried out.