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研究了淬火-回火工艺对Ti-46Al-x B合金柱状晶组织的影响。研究发现,淬火-回火工艺对Ti-46Al-x B合金的柱状晶组织具有明显的细化效果。这主要是由于温度梯度的增加和冷却过程中发生固态相变使晶界或相界面上原子错配,从而形成大量的位错,位错对晶界具有“钉扎”作用,从而细化Ti Al基合金柱状晶组织。结果表明,通过合金化元素B和热处理工艺的共同作用可以获得更为细小的Ti Al基合金柱状晶组织。这主要是由于随着B含量的增加,硼化物的析出量增加,而硼化物对位错线的进一步扩展起到了阻碍作用。从而促进了位错对晶界的“钉扎”作用,进一步细化了Ti Al基合金柱状晶组织。
The effect of quenching-tempering on the columnar crystal structure of Ti-46Al-x B alloy was studied. It is found that the quenching-tempering process has obvious thinning effect on the columnar crystal structure of Ti-46Al-x B alloy. This is mainly due to the increase of the temperature gradient and the solid phase transformation during the cooling process to mismatch the atoms on the grain boundary or phase interface to form a large number of dislocations which have a “pinning” effect on the grain boundaries and thus fine TiAl-based alloy columnar crystal structure. The results show that the finer TiAl-based alloy is obtained by the combination of alloying element B and heat treatment process. This is mainly due to the increase of B content, the increase of the amount of boride precipitated, and the boride has hindered the further expansion of the dislocation line. Thus promoting the “pinning” effect of dislocations on the grain boundaries and further refining the columnar TiAl-based alloy structure.