热处理条件对7055铝合金流变行为及再结晶机制的影响

Effect of Heat Treatment Condition on the Flow Behavior and Recrystallization Mechanisms of Aluminum Alloy 7055.

作者信息

Liao Bin, Cao Lingfei, Wu Xiaodong, Zou Yan, Huang Guangjie, Rometsch Paul A, Couper Malcolm J, Liu Qing

机构信息

International Joint Laboratory for Light Alloys (Ministry of Education), College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.

Electron Microscopy Center of Chongqing University, Chongqing University, Chongqing 400044, China.

出版信息

Materials (Basel). 2019 Jan 20;12(2):311. doi: 10.3390/ma12020311.

DOI:10.3390/ma12020311

PMID:30669505

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6356346/

Abstract

The flow behavior and the microstructural evolution of aluminum alloy 7055 in two heat treatment conditions (homogenized vs. pre-rolled, solution treated, stretched and naturally aged (T3)) were investigated for a height reduction of 60% with deformation temperatures ranging from 370 °C to 450 °C and strain rates ranging from 0.01 s to 10 s. Flow stress decline ratio maps as a function of deformation temperature and strain rate were produced along with processing maps at a strain of 0.8 to reveal optimum hot-working conditions for deformation at strain rates of 0.01 s to 0.1 s. The results showed that the stress drop ratio during deformation is higher for the homogenized condition than for the pre-rolled, T3 condition. A higher degree of recrystallization after deformation was observed in the pre-rolled, T3 condition due to finer second phase particles, smaller grain size, and more numerous sub-grains. The mechanism for deformation softening is discussed in the context of grain boundary characteristics.

摘要

研究了铝合金7055在两种热处理条件下（均匀化处理与预轧制、固溶处理、拉伸和自然时效（T3））的流变行为和微观结构演变，变形程度为60%，变形温度范围为370℃至450℃，应变速率范围为0.01s⁻¹至10s⁻¹。绘制了流动应力下降比图，该图是变形温度和应变速率的函数，并绘制了应变0.8时的加工图，以揭示应变速率为0.01s⁻¹至0.1s⁻¹时变形的最佳热加工条件。结果表明，均匀化处理条件下变形过程中的应力下降比高于预轧制T3条件。由于第二相颗粒更细小、晶粒尺寸更小以及亚晶粒数量更多，在预轧制T3条件下观察到变形后更高程度的再结晶。在晶界特征的背景下讨论了变形软化机制。