GH4169合金热压缩变形行为与枝晶组织的关系  

The Relationship Between the Deformation Behavior and Dendrite Structure of GH4169 Alloy Under Thermal Compression

作　　者：张燕[1] 吕晓华[1] 崔建弘[1] 

机构地区：[1]河北工程技术学院,河北石家庄050000

出　　处：《铸造技术》2017年第10期2393-2397,共5页Foundry Technology

基　　金：2014年度河北省第十届社会科学立项研究课题(SZ201429)

摘　　要：对铸态GH4169合金不同部位试样进行了不同热压缩试验,利用扫面电子显微镜、金相显微镜、EBSD研究了该合金在不同热压缩条件下的变形行为与枝晶组织的关系,并探讨了其机理。结果表明:高温热变形过程中,铸态GH4169合金的变形抗力与形变量、应变速率以及变形温度有关。变形量增大、应变速率增高、温度降低会导致变形抗力增大。当变形量为45%时,高应变速率和高温对动态再结晶更加有利。当加载方向与一次枝晶方向垂直时,材料的热变形机制为二次枝晶滑动,由此会导致应变速率敏感因子变大。初始组织为等轴枝晶的样品最有利于动态再结晶,中心粗柱状晶样品具有最大的变形抗力,而边缘细柱状晶样品再结晶比例最低、变形抗力最小。Samples at different positions of the as-cast GH4169 alloy was investigated for the different hot compression test, the hot compression deformation behavior and the relationship between the dendritic structures under different conditions were studied with scanning electron microscope, metallographic microscope, EBSD, and to explore its mechanism. The results show that the deformation resistance of as cast GH4169 alloy is related to the deformation, strain rate and deformation temperature. The deformation resistance increases with the increase of deformation, strain rate and temperature. When the deformation is 45%, high strain rate and high temperature are more favorable for dynamic recrystaUization. When the loading direction is perpendicular to the direction of a dendrite, the thermal deformation mechanism of the material is two times of dendrite sliding, which will lead to strain rate sensitivity factor increasing, the initial microstructure of equiaxed dendrite samples the dynamic recrystallization to center, coarse columnar crystal samples have the maximum deformation resistance, and the edge of fine colunmar sample recrystallization, the lowest proportion of the minimum resistance of deformation.

关 键 词：铸态GH4169合金 变形抗力 应变速率敏感因子 枝晶组织 变形行为 

分 类 号：TG132.3[一般工业技术—材料科学与工程]