CAJ | 학술논문

在Gleeble-1500热模拟机上对7150铝合金进行高温热压缩实验,研究该合金在变形温度为300~450 ℃和应变速率为0.01～10 s~(-1) 条件下的流变应力行为.结果表明:流变应力在变形初期随着应变的增加而增大,出现峰值后逐渐趋于平稳;峰值应力随着温度的升高而减小,随着应变速率的增大而增大;可用包含Zener-Hollomon参数的Arrhenius双曲正弦关系来描述合金的热流变行为,其变形激活能为226.698 8 kJ/mol;随着温度的升高和应变速率的降低,合金中拉长的晶粒发生粗化,亚晶尺寸增大,再结晶晶粒在晶界交叉处出现并且晶粒数量逐渐增加;合金热压缩变形的主要软化机制由动态回复逐步转变为动态再结晶.
재Gleeble-1500열모의궤상대7150려합금진행고온열압축실험,연구해합금재변형온도위300~450 ℃화응변속솔위0.01～10 s~(-1) 조건하적류변응역행위.결과표명:류변응력재변형초기수착응변적증가이증대,출현봉치후축점추우평은;봉치응력수착온도적승고이감소,수착응변속솔적증대이증대;가용포함Zener-Hollomon삼수적Arrhenius쌍곡정현관계래묘술합금적열류변행위,기변형격활능위226.698 8 kJ/mol;수착온도적승고화응변속솔적강저,합금중랍장적정립발생조화,아정척촌증대,재결정정립재정계교차처출현병차정립수량축점증가;합금열압축변형적주요연화궤제유동태회복축보전변위동태재결정.
The flow stress behavior of 7150 aluminum alloy during hot compression deformation was studied by thermal simulation test at the deformation temperature of 300-450 ℃ and the strain rate of 0.01-10 s~(-1) on the Gleeble-1500 thermal-mechanical simulator. The results show that the flow stress increases with increasing strain and tends to be constant after a peak value. The peak stress increases with increasing strain rate, and decreases with increasing deformation temperature, which can be represented by a Zener-Hollomon parameter in the hyperbolic sine equation with the hot deformation activation energy of 226.6988 kJ/mol. With increasing temperature and decreasing strain rate, the elongated grains in the deformed samples are coarsened and the size of subgrain increases; the number of fine grain in grain boundary also increases, indicating that the main softening mechanism of the alloy during hot compression deformation transforms from dynamic recovery to dynamic recrystallization.