摘要
目的研究应变速率对衬板轧制AZ31镁合金显微组织和力学性能的影响规律,分析应变速率对AZ31镁合金组织细化和性能的作用机理,解决传统轧制下AZ31镁合金性能偏低的问题。方法将商用AZ31镁合金板材在350℃下以不同应变速率(7.5、10.9、15.3 s^(-1))进行衬板轧制,探究应变速率对AZ31镁合金显微组织和力学性能的影响。结果随衬板轧制应变速率的增加,镁合金中孪晶数量减少,显微组织由变形晶粒和动态再结晶晶粒组成的混晶组织转变为等轴的动态再结晶组织,平均晶粒尺寸增加。基面织构主要组分由{0001}1010和{0001}2110向{0001}1010转变。当应变速率从7.5s^(-1)增加到15.3s^(-1)时,镁合金的YS从230 MPa下降到183MPa,而UTS最初从281MPa增加到290MPa,然后又下降到265MPa。此外,EL从3.9%逐渐增加到14.6%。结论衬板轧制的应变速率显著影响了镁合金板材的显微组织、织构和力学性能,提高轧制应变速率可促进镁合金发生动态再结晶,从而细化晶粒、弱化基面织构,有助于提高镁合金的屈服强度和伸长率。合理选择镁合金衬板轧制的应变速率能够有效改善其综合力学性能,为后续的高强塑性镁合金制备提供一种行之有效的方法。
The work aims to study the effect of strain rate on the microstructure and mechanical properties of AZ31 magne-sium alloy during the hard plate rolling,analyze the role of rolling strain rate in refining the microstructure and improving the properties of AZ31 magnesium alloy,and solve the problem of low performance of AZ31 magnesium alloy in traditional rolling.The AZ31 magnesium alloy plate was rolled at 350℃at different strain rates(7.5,10.9,15.3 s^(-1))through the hard plate rolling,and the effect of strain rate on the microstructure and mechanical properties of AZ31 magnesium alloy was investigated.With the increase of the strain rate for the hard plate rolling,the number of twins in magnesium alloy decreased,and the microstruc-ture transformed from a mixed microstructure composed of deformed grains and dynamic recrystallized grains to an equiaxed dynamic recrystallized structure,and the average grain size increased.The main component of the basal texture changed from{0001}1010 and{0001}2110 to{0001}1010.When the strain rate increased from 7.5 s^(-1)to 15.3 s^(-1),the YS of magne-sium alloy decreased from 230 MPa to 183 MPa,while the UTS initially increased from 281 MPa to 290 MPa and then de-creased to 265 MPa.In addition,the EL increased gradually from 3.9%to 14.6%.The strain rate of hard plate rolling signifi-cantly affects the microstructure,texture,and mechanical properties of AZ31 magnesium alloy plate.Increasing the rolling strain rate can promote dynamic recrystallization in magnesium alloy,thereby refining the grain size,weakening the basal texture,and improving the yield strength and elongation.Choosing an appropriate strain rate for the hard plate rolling can effectively im-prove its comprehensive mechanical properties,providing a practical method for the subsequent production of high-strength and ductile magnesium alloys.
作者
胡雕
马旻
陈曦
刘阳
刘龙飞
HU Diao;MA Min;CHEN Xi;LIU Yang;LIU Longfei(School of Materials Science and Engineering,Hunan University of Science and Technology,Hunan Xiangtan 411201,China)
出处
《精密成形工程》
北大核心
2024年第11期65-74,共10页
Journal of Netshape Forming Engineering
基金
湖南省自然科学基金(2020JJ5181)。
关键词
AZ31镁合金
应变速率
衬板轧制
显微组织
力学性能
AZ31 magnesium alloy
strain rate
hard plate rolling
microstructure
mechanical properties
