Ti-1300合金中β/β晶界区β→α相变晶体学特征的EBSD分析  

Crystallographic Characteristics of β→α Phase Transformation at β Grain Boundaries in Ti-1300 Alloy

作　　者：郭军[1] 金头男[1] 赵永庆[2] 舒群[1] 杜社军[3] 

机构地区：[1]北京工业大学,北京100124 [2]西北有色金属研究院,西安710016 [3]西部超导材料科技股份有限公司,西安710018

出　　处：《稀有金属材料与工程》2017年第4期979-984,共6页Rare Metal Materials and Engineering

摘　　要：利用电子背散射(EBSD)技术研究了近β型Ti-1300合金中次生α相的晶体学取向、几何生长方向、数量和分布与β相晶界特性之间的关系,以获悉次生α相的形核及其变体选择的本质。近β型Ti-1300合金经910℃固溶2 h+水淬处理,合金中出现一定比例的<110>_(_(70.5°))特殊晶界。该合金在910℃随炉缓慢冷却时,由β→α相变而来的次生α相与β相晶界的特性有明显关系。普通β/β晶界处生成的晶界α相自身取向不唯一,对自晶界α相变体形核作用不大,其两侧自晶界α相数量偏少;大角度特殊晶界<110>_(70.5°)两侧β晶粒存在共同的(110)面,这种取向有利于晶界α相为自晶界α变体提供异质形核,引发α变体在晶界两侧选择性生长;小角度特殊晶界<110>10.5°也会引发α变体选择性生长,但和大角度晶界不同,其选择性生长也可能只发生在晶界的一侧。In order to obtain the essence of the nucleation of secondary a phase and its variants selection in nearly fl-type Ti-1300 alloy, the relationship of the crystal orientation, geometric growth direction, quantity, distribution of secondary a-phase to fl-phase grain boundaries properties was investigated by electronic backscatter diffraction （EBSD）. Results show that a certain percentage of 〈110〉 70.50 special boundaries occurs in the alloy with solid solution for 2 h at 910 ℃ followed by water quenching. When the alloy is slowly cooled in the furnace at 910 ℃, there is a significant relationship between the secondary a phase from β→α phase transformation and fl-phase grain boundaries properties. The orientation of a phase in common fl/fl grain boundary is not unique, which has little effect on the nucleation of the self grain boundary a phase variations, and there is less self grain boundary a phase of both sides. Both sides of the fl grain with special high angle grain boundaries （〈110〉70.5°） have the same （110） plane, which favors the formation of the heterogeneous nucleation of the self-grain boundary a phase variants, and causes selective growth of the a variant in both sides of grain boundary. Besides, special small-angle grain boundaries （〈110〉10.5°） also cause a variant＇s selective growth, but the growth may only occur on one side of the grain boundary, which is different from that of high-angle grain boundaries.

关 键 词：Ti-1300合金 相变 Burgers取向 生长方向 电子背散射(EBSD) 

分 类 号：TG146.23[一般工业技术—材料科学与工程]