摘要
通过将不同冷却阶段的试样淬火,研究了再结晶诱发的块状过冷Ni54.6Pd45.4合金的组织演化。结果表明,当过冷度大于临界过冷度时,由于再结晶引起的晶粒细化起始于快速凝固阶段结束之时,并在随后的冷却过程中发展。再结晶初始阶段由于晶核形成,导致晶粒尺寸降低。随后,由于晶粒的相互吞并长大占主导地位,晶粒尺寸增加。随着凝固前过冷度的增加,快速凝固的枝晶骨架间的变形程度增加,再辉温度在高温阶段停留的时间也降低。最终使得再结晶晶粒尺寸下降。
Structure evolution driven by recrystallization in the bulk undercooled Ni54.6Pd45.4 alloy was investigated by quenching the sample at different cooling stages. The results show that recrystallization of the solid beyond the critical undercooling for grain refinement starts at the end of rapid solidification, and develops during slow solidification and subsequent cooling process. At the initial stage of recrystallization, nuclei successively formed in the sample, And the grain size decrease. At the later stage, annexation of grains dominates the recrystallization process, due to which the number of grain size increases. As undercooling before solidification increases, the deformation degree in the rapidly solidified dendrite net rises, and the recalescence temperature as well as the duration at high temperature decreases. Consequently the recrystallization grain size structure decreases.
出处
《铸造技术》
CAS
北大核心
2010年第3期298-301,共4页
Foundry Technology
关键词
淬火
再结晶
显微组织
过冷度
Quenching
Recrystallization
Microstructure
Undercooling
