Feng Xuhui, Sun Youping, Lu Yuwei, He Jiangmei, Liu Xiao, Wan Siyu
School of Mechanical and Transportation Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China.
Key Laboratory of High Temperature Wear Resistant Materials Preparation Technology of Hunan Province, Hunan University of Science and Technology, Xiangtan 411201, China.
Materials (Basel). 2020 Jul 3;13(13):2969. doi: 10.3390/ma13132969.
High strain rate rolling (HRSS) of a ZK60 magnesium alloy at 300 °C with a strain rate from 5 s to 25 s was used to research the effect of the rate on the mechanical properties and damping capacity of the ZK60 alloy. The results show that as the strain rate increases, the tensile strength decreases from 355 MPa at 25 s to 310 MPa at 5 s. Two damping peaks (P1 and P2) are detected in the high strain rate rolled ZK60 alloys at different strain rates. The P1 peak appears at low temperatures and is caused by grain boundaries sliding. The P2 peak appears at high temperatures and is caused by recrystallization. As the strain rate increases from 5 to 20 s, the dynamic recrystallization (DRX) volume percent rises and the dislocation density decreases, both of which cause the P1 peak to become more and more obvious, and activation energy rises. At the same time, the dislocation density decreases and leads to a decrease in the storage energy, which reduces the recrystallization driving force and shifts the P2 peak to high temperatures. When the strain rate reaches 20 and 25 s, DRX occurs fully in the sheet, so the activation energy of the P1 peak and the temperature where the P2 peak appears are basically equal.
采用在300℃下应变速率为5s⁻¹至25s⁻¹的ZK60镁合金高应变速率轧制（HRSS）工艺，研究应变速率对ZK60合金力学性能和阻尼性能的影响。结果表明，随着应变速率的增加，抗拉强度从25s⁻¹时的355MPa降至5s⁻¹时的310MPa。在不同应变速率下的高应变速率轧制ZK60合金中检测到两个阻尼峰（P1和P2）。P1峰出现在低温下，由晶界滑动引起。P2峰出现在高温下，由再结晶引起。随着应变速率从5s⁻¹增加到20s⁻¹，动态再结晶（DRX）体积分数增加，位错密度降低，这两者都导致P1峰变得越来越明显，且激活能升高。同时，位错密度降低导致储能减少，从而降低再结晶驱动力，并使P2峰向高温方向移动。当应变速率达到20s⁻¹和25s⁻¹时,板材中完全发生DRX，因此P1峰的激活能和P2峰出现的温度基本相等。
