Ta晶粒细化工艺及组织、织构的研究

研究了加工方法对Ta组织及织构的影响,采用径向模压(自行设计的模具)+轴向镦粗的方法,经过2个循环的变形.在真空下1100℃退火1 h,取样观察了钽的微观组织、晶粒度;研究了轧制方式对钽组织均匀性的影响,采用一次交叉轧制的方法,道次加工率为5%～10%,总变形量为70%,真空退火1200℃.经EBSD测定了不同状态下钽的织构.结果表明:模压和轧制方法对钽的力学性能和晶粒大小有重要影响,一次交叉轧制可以更有效地减小钽的各向异性并获得细晶粒,平均晶粒度为30 μm.采用模压更有利于退火态钽板中{111}织构的增强,并减少{100}.

Study on Tantalum Grain Refinement Process and Microstructure, Texture

The effects of processing methods on microstructure and textures of high purity tantalum were studied.Radial forging and axial upset forging were used for tantalum ingot firstly.The microstructure and grain size of tantalum annealed at 1000 ℃ for about 1 h in a vacuum furance after deformation were analyzed.Then the effects of different rolling methods on microstructure uniformity were discussed by single cross-rolling,reduction in pass of 5% to 10%,total deformation of 70% and annealed at 1200℃.Textures of different samples were determined by EBSD.The results show that forging and rolling processes can make a great difference in microstructure and textures.Fine microstructure with average grain size about 30 μm by single cross-rolling is obtained.Radial forging and axial upset forging can enhance {111}and reduce {100}.There are strong {111} and little {100} in tantalum plates after once cross rolling and annealing.