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nucleant for Mg-Al magnesium alloys. Key words: Mg-Al alloys; grain refinement; carbon inoculation; mechanical properties; mechanism 1 Introduction Magnesium alloys have been widely used in recent... following standard procedures. Specimens were first mechanically polished and finally etched in acetic picral and observed under a Laitz-DMRX microscope. In order to observe the nucleant of alloys, another......
would form in the melt and act as an efficient nucleant, resulting in very refined grain and an equiaxed grain structure. Sc element reduces the number of eutectic phases formed during solidification......
利用复合工业废渣制备CaO-MgO-Al2O3-SiO2微晶玻璃南雪丽1,卢学峰2,傅希圣1(1.甘肃省兰州市兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室2.兰州理工大学 有色金属合金及加工教育部重点实验室,兰州 730050)摘 要:以镍渣和粉煤灰为主要原料采用熔融法制备微晶玻璃.利用正交设计方法确定工业废渣复合微晶玻璃的最佳原料配比:镍渣34%,粉煤灰28%,钙盐18%,钠盐4%,形核剂TiO2+ZnO(适量),还原剂11%.通过XRD,SEM分析技术,物理化学性能测试等手段确定微晶玻璃的主晶相,......
the nucleation of α(Al) at small undercoolings while effective solutes provide constitutional undercooling to trigger further nucleation on adjacent nucleant particles. In spite of the common...] developed for Mg-Al based alloys and Ti alloys show relatively low grain refining efficiency in comparison with that expected from the combined effect of nucleant particles and solutes. Therefore......
Al3Sc or Al3Zr particles, which can behave as potent nucleant particles for Al or inhibit the migration of grain boundary or subboundary, thus will lead to the grain refinement [4,15-17]. The mechanisms...), was put forward to explain the relationship between grain size and the combined effects of nucleant particle potency and solute content, which is given by  ......
as a result of constitutional undercooling generated by the growth of a grain adjacent to a nucleant particles suspended in the melt[8-11]. There are two factors which can enhance the number of successful nucleation events. The first is the solute elements present in the melt and the other is the number and potency of the nucleant particles. The effect of solute elements on the grain refinement can......
on the borides (TiB2 or others) and Al3Ti particles present in the master alloy [1-3,7,8], while the latter assumes that both the existence of nucleant particles and the amount of segregating... segregates to the nucleant–liquid interface, which leads to constitutional supercooling, and other nucleant particles get activated for the nucleation. Unexpectedly, a sample deformed by HPT shows weak......
of nuclei. The further study[5-6] showed that the nucleant particles seldom aggregate at the bottom of the ingots. The un-changeable content of titanium and evenly distribution of titanium in the Al-based... of heterogeneous nucleant particles [J]. Acta Mater, 2001, 49: 1867-1878. [3] LIU Zhi-yong, WANG Ming-xing, WENG Yong-gang, SONG Tian-fu, XIE Jing-pei and HUO Yu-ping. Grain refinement effects of Al-based alloys......
nucleant potencies using Eq.(8). Fig.2(b) is the experimental data showing the effect of solute titanium additions on the grain size for more potent nucleants, e.g. TiB2, and for less potent nucleants where... nucleant potencies using Eq.(8). Fig.3(b) is the experi- mental data showing the effect of solute copper additions on the grain size[12]. Fig.3 Calculated variation of grain size with copper......
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