Crystallography of Zr poisoning of Al-Ti-B grain refinement using edge-to-edge matching model
来源期刊:中南大学学报(英文版)2013年第10期
论文作者:HUANG Yuan-chun(黄元春) XIAO Zheng-bing(肖政兵) LIU Yu(刘宇)
文章页码:2635 - 2642
Key words:crystallography; Al-Ti-B; Zr; edge-to-edge matching model; poisoning mechanism
Abstract: The mechanism of zirconium poisoning on the grain-refining efficiency of an Al-Ti-B based grain refiner was studied. The experiment was conducted by melting Al-5Ti-1B and Al-3Zr master alloys together. The edge-to-edge matching model was used to investigate and compare the orientation relationships between the binary intermetallic compounds present in the Al-Ti-B-Zr system. The results show that the poisoning effect probably results from the combination of Al3Zr with Al3Ti and the decreased amount of Ti solute, for Al3Ti particles have good crystallographic relationships with Al3Zr. Totally six orientation relationships may present between them, while they play vital roles in grain refinement. TiB2 particles appear to remain unchanged because of a bit large misfit. Only one orientation relationship may present between them to prevent Al3Zr phase from forming on the surface of TiB2, though TiB2 is agglomerated. The theoretical calculation agrees well with the experimental results. The edge-to-edge matching model is proved to be a useful tool for discovering the orientation relationships between phases.
HUANG Yuan-chun(黄元春)1, 2, XIAO Zheng-bing(肖政兵)1, 2, LIU Yu(刘宇)1, 2
(1. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
2. Light Alloy Research Institute, Central South University, Changsha 410012, China)
Abstract:The mechanism of zirconium poisoning on the grain-refining efficiency of an Al-Ti-B based grain refiner was studied. The experiment was conducted by melting Al-5Ti-1B and Al-3Zr master alloys together. The edge-to-edge matching model was used to investigate and compare the orientation relationships between the binary intermetallic compounds present in the Al-Ti-B-Zr system. The results show that the poisoning effect probably results from the combination of Al3Zr with Al3Ti and the decreased amount of Ti solute, for Al3Ti particles have good crystallographic relationships with Al3Zr. Totally six orientation relationships may present between them, while they play vital roles in grain refinement. TiB2 particles appear to remain unchanged because of a bit large misfit. Only one orientation relationship may present between them to prevent Al3Zr phase from forming on the surface of TiB2, though TiB2 is agglomerated. The theoretical calculation agrees well with the experimental results. The edge-to-edge matching model is proved to be a useful tool for discovering the orientation relationships between phases.
Key words:crystallography; Al-Ti-B; Zr; edge-to-edge matching model; poisoning mechanism