TC11钛合金棒材显微组织等轴细晶化工艺研究

TECHNOLOGICAL STUDIES ON EQUIAXED GRAIN REFINEMENT IN TC11 Ti ALLOY BAR

本文对TC11钛合金棒材显微组织不均匀缺陷产生原因及消除途径进行了研究。结果表明,由于铸锭最初锻造温度在β相区,随后两相区锻造变形量不大且分布不均匀,致使部分晶界α和二次α聚集并粗化呈块状,或沿主变形方向拉长呈条状,或遗留下原晶界α。若采用(α+β)中间形变热处理+β处理、水冷+再结晶退火、空冷的工艺,可完全消除晶界α,拉长α和块状α相,获得均匀细小等轴α组织,初生等轴α相的平均直径可细化至1.9μm。

The formation reason and elimination method of non-uniform microstructure defects in TC11 Ti alloy bar have been studied. The coagulating and coarsening into block of the part of grain boundary α and secondary α seem to be caused by the ingot cogging and initial forging temperature in the β region as well as no more enough deformation and uneven distribution. The grain α, elongated α and blocky α may be finally eliminated by adopting the technique of (α+β) thermomechanical processing+β processing, W. Q.+recrystallization annealing, A. C., thus the size of uniform and fine equiaxed α structure is believed to be reduced to 1.9258μm.