Ti-6246中α相转变织构的形成机制

Mechanism of α Texture Formation of Ti-6246 Alloy Induced by β Forging Process

利用EBSD研究了β单相区锻造Ti-6246饼坯的显微组织和晶体取向。结果表明,β锻造的Ti-6246合金有网篮组织,原始β晶粒沿着金属的流动方向拉长。β相呈现<100>_β与饼坯压缩方向平行的强丝织构。次生α相的织构类型与β相符合Burgers取向关系。当相邻原始β晶粒具有相近<110>方向时,在该β/β晶界两侧析出的次生α相的晶体c轴将沿着这一共同的<110>方向,即发生变体选择,导致α相在{0001}极图上的最大织构密度明显高于β相在(110)极图上的最大织构密度。

The microstructure and texture of β forged Ti-6246 biscuit were studied using optical microscope（OM） and electron backscattered diffraction（EBSD）. It is found that a mesh-basket like microstructure with elongated β-phase grains along the metal flow direction was formed after forging the Ti-6246 biscuit in β-phase state. The β-phase presented a strong 100 fiber texture parallel to the deformation direction. The texture components of transformed α-phase are controlled by the parent β-phase, but the intensity of the transformed α-phase is influenced by variant selection. The variant selection, the α-phase colonies with a common c-axis often situated at the prior β-phase boundary when the neighboring β-phase grains share a common {110} plane, is one of the important reasons for the strengthened α-phase texture intensity.