平头压痕试验确定铝合金2A12的蠕变剩余寿命研究

Prediction of Creep Residual Life of Aluminum Alloy 2A12 by Using Indentation Test Method with Flat Cylindrical Indenters

基于平头压痕理论和蠕变损伤理论,提出了采用平头压痕试验和拉伸蠕变试验相结合的方法来确定铝合金2A12的蠕变剩余寿命。具体思路为:(1)由拉伸蠕变试验(通过控制试验时间)获得不同损伤的试样;(2)针对受损试样,由压痕加卸载试验确定不同损伤所对应的卸载曲线顶部斜率;(3)通过计算获得拉伸蠕变试样的损伤量;(4)得到卸载曲线顶部斜率与损伤的关系曲线,并以此为标定曲线推断出铝合金拉伸蠕变损伤试样的剩余寿命。

A method of predicting the residual creep life of aluminum alloy 2A12 by using indentation test method with flat cylindrical indenters was proposed. There were four steps included in the method. First, specimens with different creep damage levels were obtained by the tensile creep testing （by control testing time）. Second, the above damage specimens were put to the indentation testing, and then the typical load-displacement curves were yielded. Third, correlation equations were used to get pre-damage values. In the end, the residual creep life can be determined by the relationship between the slope of the initial portion of the unloading curve and the damage values.