以工业化等离子冷床炉熔炼的TC1合金为研究对象,结合实际生产流程,并借助于中子衍射技术,研究不同轧制工艺对TC1板材显微组织与性能演变的影响,揭示组织结构与力学性能之间的关系.结果表明,冷床炉熔炼的铸锭组织为魏氏组织.经过轧制后,a集束发生扭曲和破碎.单向轧制变形a相沿轧向排列比换向轧制更为明显.退火后,板材中变形a相发生等轴化.经过单向轧制和换向轧制后,轧制板材均表现为柱面织构类型,这是板材横向屈服强度均明显高于其轧向屈服强度的主要原因.
Plasma arc cold hearth melting(PAM) is an effective technology to produce high purity titanium alloy ingots which are widely used in aeronautic and astronautic industries. To date, the development of PAM in our country is still at initial stage. It is necessary to investigate the melting parameters of PAM and the followingthermal mechanical processing of the ingots fabricated by PAM. In this study, the TC1 alloy ingots casted by PAM were cogged at b transus temperature and then rolled by unidirectional rolling and cross rolling in the a+b phase field. The typical widmanstatten structure of cast- ingots turned to transformed b morphology after cogging at b transus temperature in which the a phases forms in smaller colonies of laths. After the unidirectinal rolling in the a+b phase field, the a colonies were distorted and the a laths re-arranged along the rolling direction, while they had weaker directivity after cross rolling. The sheets rolled by both unidirectional and cross rolling showed typical prismatic texture. After annealing treatment below the b transus temperature, the a phases turned to equiaxial morphology. The ambient yield strength of the sheet in transverse direction was significantly higher than in rolling direction, which could be attributed to the strong prismatic texture introduced by hot rolling process.