Effect of pack rolling on microstructures and tensile properties of as-forged Ti-44Al-6V-3Nb-0.3Y alloy
Effect of pack rolling on microstructures and tensile properties of as-forged Ti-44Al-6V-3Nb-0.3Y alloy
复制标题
堆轧对锻态Ti-44Al-6V-3Nb-0.3Y合金显微组织和拉伸性能的影响
DOI：
10.1016/j.intermet.2011.10.003
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发表时间：
2012-02-01
期刊：
影响因子：
4.4
通讯作者：
Yang, F.
中科院分区：
文献类型：
--
作者：
Niu, H. Z.;Kong, F. T.;Yang, F.
研究了Ti-44 Al-6V-3 Nb-0.3Y（at. %）合金热轧前后的力学性能进行了系统研究。扫描电镜结果表明，轧制的TiAl板材的特点是完全动态再结晶的显微组织，除了一些细化的片层殖民地在后端，这主要是由于在包套锻造和随后的包轧过程中的温度下降。通过TEM分析，发现了γ相在热轧过程中发生α板条分解而粗化的现象;同时，通过EBSD测量，对锻态和轧制态的相组成和晶粒特征进行了表征和比较。拉伸性能测试结果表明，热轧后合金的室温抗拉强度明显下降，横向屈服强度由620 MPa下降到520 MPa沿着横向屈服强度由680 MPa下降到598 MPa，横向屈服强度由620 MPa下降到485 MPa，抗拉强度由680 MPa下降到556 MPa。详细解释了拉伸强度下降的原因。经单相区热处理后，变形后的TiAl合金中β相被消除，拉伸性能明显提高。皇冠版权所有（C）2011由爱思唯尔有限公司出版。保留所有权利。
The microstructures and tensile properties of Ti-44Al-6V-3Nb-0.3Y (at. %) alloy before and after hot rolling were investigated systematically. SEM results indicated that the as-rolled TiAl sheet was characterized by completely dynamically recrystallizated microstructures, except some refined lamellar colonies in the back end, which are primarily caused by the temperature drop during canned forging and subsequent pack rolling. By TEM analysis, the coarsening of gamma lamellae by alpha lath decomposition during hot rolling are found. Meanwhile, by EBSD measurements, the phase composition and grain features of the as-forged and the as-rolled conditions were characterized and compared. Additionally, the tensile properties were tested to find that the room temperature tensile strength decreased obviously after hot rolling, with yield strength decreasing from 620 MPa to 520 MPa along transverse direction (TD) and to 485 MPa in rolling direction (RD), and the UTS from 680 MPa to 598 MPa and 556 MPa respectively. The reason for the degradation of the tensile strength is interpreted detailedly. After being heat-treated in single a phase field, beta phase was eliminated from current deformed TiAl alloy and the tensile properties were enhanced obviously. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.