Influence of quenching cooling rate on residual stress and tensile properties of 2A14 aluminum alloy forgings
Influence of quenching cooling rate on residual stress and tensile properties of 2A14 aluminum alloy forgings
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DOI：
10.1016/j.msea.2016.08.017
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发表时间：
2016-09
期刊：
影响因子：
6.4
通讯作者：
Yuxun Zhang;You-ping Yi;Shi-quan Huang;D. Fei
中科院分区：
文献类型：
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作者：
Yuxun Zhang;You-ping Yi;Shi-quan Huang;D. Fei
为平衡铝合金淬火残余应力和力学性能，采用数值模拟和淬火实验相结合的方法，研究了冷却速度对铝合金淬火残余应力和拉伸性能的影响。在淬火实验过程中，2A 14铝合金样品用不同的水温（20 °C、70 °C、100 °C）和分步淬火工艺处理。用X射线衍射仪（XRD）测定了残余应力。在此之前，研究了猝灭敏感性。为此，测量了时间-温度-性能（TTP）曲线，并利用透射电子显微镜（TEM）观察了合金的显微组织。结果表明，在300 ~ 400 °C的淬火敏感温度范围内，2A 14铝合金的力学性能主要取决于冷却速度。较低的冷却速率会降低合金的抗拉强度和屈服强度，这是由于细小析出相的数量减少，而残余应力则随着塑性应变的减小和塑性变形的不均匀程度而减小。随着冷却速率的降低，残余应力的变化速度比拉伸性能的变化速度快。因此，使用温水（70 °C）来平衡140 mm厚2A 14铝合金锻件的残余应力和拉伸性能，因为它可以实现低冷却速率。此外，通过将这一特性与材料的淬火敏感性相结合，分级淬火与温水（70 °C）淬火相比，通过在淬火敏感性范围内提高冷却速率，在其他范围内降低冷却速率，获得了相似的拉伸性能和更低的残余应力。
To balance the quenching residual stress and the mechanical properties of aluminum alloys, the influence of cooling rate on the residual stress and tensile properties was investigated by numerical simulation and quenching experiments. During the quenching experiments, 2A14 aluminum alloy samples were treated with different water temperatures (20 °C, 70 °C, 100 °C) and a step quenching process. X-ray diffraction (XRD) was used to measure the residual stress. Prior to them, the quenching sensitivity was studied. For this purpose, the time-temperature-properties (TTP) curves were measured and the alloy microstructure was observed using transmission electron microscopy (TEM). The results indicated that the mechanical properties of 2A14 aluminum alloys were mainly determined by the cooling rate within the quenching sensitive temperature range from 300 to 400 °C. Lower cooling rates reduced the tensile strength and yield strength due to a decrease amount of fine precipitates, and reduced the residual stress with the reduction of plastic strain and the degree of inhomogeneous plastic deformation. In addition, the residual stress changed faster than the tensile properties with decreasing cooling rate. Therefore, warm water (70 °C) was used to balance the residual stress and tensile properties of 140-mm-thick 2A14 aluminum alloy forgings, since it can achieve low cooling rates. Furthermore, by combining this characteristic and the material quenching sensitivity, step quenching produced similar tensile properties and lower residual stress, compared with the sample quenched in warm water (70 °C), by increasing cooling rate within quenching sensitivity range and reducing it in other ranges.