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precipitates as the heterogeneous nucleation sites for primary α-Mg phases. Microscopic analysis for the location of the Al8(Mn, Fe)5 precipitate explains that the Al8(Mn, Fe)5 precipitate is the effective heterogeneous nucleation site for the primary α-Mg phase. It was also observed that increase of the Mn content in the melt and the cooling rate below to the solid/liquid two-phase region resulted......
(HCP) crystal structure can serve as the nucleating sites of α-Mg during solidification, and heterogeneous nucleation is the main reason of the grain refinement of α-Mg grains. Key words: Mg-7Al-0.4Zn-0.2Mn alloy; Al3Ti4B; grain refinement; heterogeneous nucleation 镁合金是迄今在工程应用中最轻的金属结构材料, 具有比强度高, 比刚度高, 阻尼减震性能好, 电磁屏蔽性能和机械加工性能优异的特点, 被誉为"21世纪最具发展潜力和前途的绿色工程材料" [1-3]. 但由于镁具有密排六方(HCP)晶体结构......
is relative to the heterogeneous nucleation of carbon-containing cores in the melt. When Mn content is low and dissolves into the melt, the nucleating potent of carbon-containing cores would not be influenced...: magnesium alloy; Mn; grain refinement; heterogeneous nucleation Mg-Al系合金是目前工业中使用量最大的镁合金系列.但该类镁合金的铸造件在生产过程中常常由于初生枝晶过分粗大,导致疏松,偏析,热裂等铸造缺陷的发生[1-3].因此,控制得到细致均匀的等轴晶组 织是改善Mg-Al系合金铸造性能和提高合金铸锭质量的重要途径.研究表明[3-4],杂质元素如......
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, 2013, 1(1): 2-22. [2] 杨 伟, 殷海眯, 商景利, 王 祥, 刘吕果. SiC颗粒参与下快冷镁合金异质形核与高温晶粒长大[J]. 中国有色金属学报, 2017, 27(2): 243-250. YANG Wei, YIN Hai-mi, SHANG Jing-1i, WANG Xiang, LIU Lü-guo. Heterogeneous nucleation... with the addition of 1%Y, which promotes heterogeneous nucleation of primary phase and is beneficial to grain refinement. Consequently, the minimum average grain size is merely 13 μm......
固态化合物对钢液非均质形核的触媒作用潘宁1,宋波1,翟启杰2(1.北京市北京科技大学 冶金与生态工程学院2.上海大学 材料科学与工程学院,上海200072)摘 要:对钢液中各种固态化合物基底与形核相(δ-Fe和γ-Fe)的价电子结构进行了计算,基于静电作用理论和经验电子理论提出了基底和形核相之间的特征参量△ρ,并对△ρ与钢液非均质形核触媒作用的关系进行了分析和讨论.结果表明:基底和形核相之间的特征参量△ρ越大,非均质形核作用越好.关键词:静电作用; 经验电子理论; 非均质形核; 钢液......
铝酸钙夹杂物的生成机制研究王敏1,包燕平1,崔恒1,吴华杰1,李太全1(1.北京市北京科技大学 冶金与生态工程学院)摘 要:运用异质形核理论解释了钢中钙对夹杂物变性的机制过程,计算得出1 873 K下w[Al]s为0.03%时,均质形核生成Al2O3钢中溶解氧的质量分数需达到39.2×10-6,而当反应达到平衡后钢中溶解氧的质量分数为3.3×10-6.脱氧后加入钙靠均质形核很难生成CaO,钙,氧原子主要以Al2O3质点为核心在其表面上生成,生成反应为:[Ca]+(x+1/3)Al2O3=CaO·xAl2O3+2......
Polytechnical University, Xi an 710072, China摘 要:The heterogeneous nucleation behaviors of NH4Cl crystal on rough aluminum substrate surface immerged in NH4Cl-H2O solution were experimentally analyzed, and the influence mechanism of the micro/nano-scale surface structures on heterogeneous nucleation was investigated. It has been shown that wettability......
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after the magnesium treatment, by which the heterogeneous nucleation of TiN was promoted it; therefore, favorable nucleation sites were provided for further refining the high-temperature ferrite phase. Key words: magnesium treatment; peritectic steel; TiN; heterogeneous nucleation; thermodynamic analysis Cite this article as: QU Tian-peng, WANG De-yong, WANG Hui-hua, HOU Dong, TIAN Jun. Thermodynamic......