(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083；
2. 中南大學(xué) 有色金屬材料科學(xué)與工程教育部重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410012)
摘 要: 通過采用掃描電鏡(SEM)、能譜儀(EDS)、X射線衍射(XRD)等對(duì)Al-Ti-Zr-C與Al-Ti-Zr-B試驗(yàn)合金中Al3Zr、Al3Ti、TiC或TiB2等第二相粒子結(jié)合情況的觀察，研究晶粒細(xì)化劑的Zr中毒機(jī)理。結(jié)果表明：兩種實(shí)驗(yàn)鋁合金的凝固組織中Al3Zr均容易與Al3Ti結(jié)合形成聚積體，從而抑制了Al3Ti異質(zhì)形核、細(xì)化晶粒的作用，出現(xiàn)所謂晶粒細(xì)化劑的Zr中毒現(xiàn)象；而TiC、TiB2粒子基本不與Al3Zr結(jié)合，但受Al3Zr的影響出現(xiàn)了團(tuán)聚現(xiàn)象。根據(jù)邊−邊匹配晶體學(xué)模型(E2EM)計(jì)算表明：Al3Zr與Al3Ti、α-Ti具有多種可能的共格位向關(guān)系，而與TiC/TiB2粒子均只有一種可能的共格位向關(guān)系。母相−新相的共格位向關(guān)系的多少可作為晶粒細(xì)化劑設(shè)計(jì)的晶體學(xué)理論參考。
關(guān)鍵字: 晶粒細(xì)化劑；Al-Ti-C；Al-Ti-B；Zr；中毒機(jī)理
Al-Ti-C and Al-Ti-B
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. Key Laboratory of Nonferrous Metal Materials Science and Engineering, Ministry of Education,
Changsha 410012, China）
Abstract:The poisoning mechanism of zirconium on the grain-refining efficiency of Al-Ti-C and Al-Ti-B based grain refiner was been studied by observing the phases distribution between Al3Zr, Al3Ti, TiC and TiB2 particles in the Al-Ti-Zr-C and/or Al-Ti-Zr-B alloys using X-ray diffraction(XRD) and scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). The results show that Al3Zr particles are easy to combine with Al3Ti particles both in Al-Ti-Zr-C and Al-Ti-Zr-B alloys, the potency of Al3Ti performed as nucleation centers is impaired and results in the poisoning phenomenon. While TiC and TiB2 particles seem not to integrate with Al3Zr particles though the agglomeration of TiB2 particles. The calculation results of edge-to-edge matching model (E2EM) indicate that Al3Zr has a better crystallographic matching with Al3Ti and α-Ti solute than it does with TiC and TiB2 particles, which implies the quantities of the orientation relationships (ORs) between the matrix and precipitate can be used as a crystallography theoretical consultation in designing grain refiner.
Key words: grain refiner; Al-Ti-C; Al-Ti-B; Zr; poisoning mechanism
