摘要
对LY12-CZ铝合金试验件进行腐蚀和疲劳的交替试验研究,分析'腐蚀+疲劳'和'疲劳+腐蚀+疲劳'两种方式下不同的腐蚀时间及不同的温度对试验件疲劳性能的影响及疲劳断裂特性差异。对试验结果的分析处理表明,同样腐蚀条件下'疲劳+腐蚀+疲劳'较'腐蚀+疲劳'方式的试验件疲劳寿命有所增加,而且增加幅度随着预疲劳寿命的增加而降低。腐蚀钝化疲劳过程中产生的微裂纹及挤入/挤出是疲劳寿命增加的原因。在腐蚀较轻状况下,腐蚀过程的钝化有着修复疲劳微损伤的功能,在腐蚀较为严重情况下(如腐蚀时间为40 h、温度为60℃),同时也产生大量腐蚀坑缺陷成为疲劳裂纹源,使得试验件疲劳寿命增加不明显,疲劳与腐蚀交替作用的先后顺序对试验件疲劳寿命的影响无差别。
The alternate experiment of corrosion and fatigue is performed for aviation LY 12-CZ aluminum alloy specimen. Under the two kinds of action of ＂corrosion＋fatigue＂ and ＂fatigue＋corrosion＋fatigue＂, the effect on fatigue characteristic and fracture mechanics discrepancy of specimens are analyzed using the conditions of several temperatures and different durations. The discussion based on the testing results shows that the total fatigue lives of ＂fatigue＋corrosion＋fatigue＂ specimens are longer than ＂corrosion＋fatigue＂ specimens under the same corrosion condition, and the increasing amplitude of fatigue life decreases with the increase of the initial fatigue life.The microcracks and intrusions/extrusions produced at the initial fatigue blunted by corrosion are the major reasons for increased fatigue life. It seems that a modest amount of corrosion actually has a beneficial effect on the material＇s micro-damage and fatigue life by blunting of microcracks under the action of ＂fatigue＋corrosion＋fatigue＂. The micro-damage of fatigue is removed and then substituted by corrosion pits when badly corrosion （for example, corrosion time 40 h, temperature 60 ℃）. The effect on fatigue life if fatigue and corrosion are sequentially intermittent is indistinctive.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2012年第20期70-76,共7页
Journal of Mechanical Engineering
基金
国家自然科学基金资助项目(50675221
51075394)
关键词
铝合金
腐蚀坑
疲劳
腐蚀损伤
断裂
Aluminum alloy Corrosion pit Fatigue Corrosion damage Fracture
