无容器凝固已成为制备新型功能陶瓷材料的重要手段,但直至目前对二元复相陶瓷的深过冷凝固机理研究甚少.本论文采用气动悬浮技术研究了无容器凝固条件下La2O3-TiO2二元共晶陶瓷凝固组织和结构演变.按La2O3-82.8at％ TiO2共晶组分将两种粉体混匀压片烧结成陶瓷圆柱,经激光加热熔化后在触发形核和无容器凝固两种形核模式下凝固.结果表明,烧结后的陶瓷由La4Ti9O24和TiO2两相组成；用光学显微镜和扫描电镜观察了两种形核模式的陶瓷样品形貌,均为规则共晶层片结构,前者因是触发形核,过冷度小,组织较后者粗大,由表面多个形核中心向内部辐射生长；后者为深过冷凝固,组织细小并高度取向,原因是后者是均质形核,过冷度大,晶体生长方向受热流控制.
参考文献
| [1] | W.J. Yao;X.J. Han;B. Wei .Microstructural evolution during containerless rapid solidification of Ni-Mo eutectic alloys[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2003(1/2):88-99. |
| [2] | Rathz TJ.;Li D.;Workman GL.;Williams G.;Robinson MB. .Study of the containerless undercooling of Ti-Ce immiscible alloys[J].Journal of Materials Science,2001(5):1183-1188. |
| [3] | Yao WJ.;Wang N.;Wei B. .Containerless rapid solidification of highly undercooled Co-Si eutectic alloys[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2003(1/2):10-19. |
| [4] | KOHARA S;SUZUYA K et al.Glass formation at the limit of insufficient network formers[J].Science,2004,303(5564):16491652. |
| [5] | WEBER J K R;FELTEN J J et al.Glass fibres of pure and erbi um-or neodymium-doped lyttria alumina compositions[J].Nature,1998,393(6687):769-771. |
| [6] | YU J;KOSHIKAWA N;ARAI Y et al.Containerless solidification of oxide materials using an electrostatic levitation furnace in microgravity[J].Journal of Crystal Growth,2001,231:568-576. |
| [7] | Yasutomo Arai;Keiji Itoh;Shinji Kohara;Jianding Yu .Refractive index calculation using the structural properties of La_(4)Ti_(9)O_(24) glass[J].Journal of Applied Physics,2008(9):094905-1-094905-6-0. |
| [8] | Jianding Yu;Shinji Kohara;Keiji Itoh .Comprehensive Structural Study of Glassy and Metastable Crystalline BaTi2O5[J].Chemistry of Materials: A Publication of the American Chemistry Society,2009(2):259-263. |
| [9] | Yu JD;Arai Y;Masaki T;Ishikawa T;Yoda S;Kohara S;Taniguchi H;Itoh M;Kuroiwa Y .Fabrication of BaTi2O5 glass-ceramics with unusual dielectric properties during crystallization[J].Chemistry of Materials: A Publication of the American Chemistry Society,2006(8):2169-2173. |
| [10] | CHESNEY J B;SAUER H A .The system La2O3-TiO2:Phase Equilibrium and Electrical Properties[J].Journal of the American Ceramic Society,1962,45:416-422. |
| [11] | ARAI Y;ITOH K;KOHARA S et al.Refractive index calculation using the structural properties of La4Ti9O24 glass[J].Journal of Applied Physics,2008,103:094905. |
| [12] | 胡汉起.金属凝固[M].北京:冶金工业出版社,1985:215-219,244. |
| [13] | Mingjun Li;Kosuke Nagashio;Kazuhiko Kuribayashi .Containerless solidification of highly undercooled Al_2O_3-ZrO_2 eutectic melts on an aero-acoustic levitator[J].Journal of Crystal Growth,2003(3/4):625-633. |
| [14] | M. Li;K. Nagashio;K. Kuribayashi .Containerless solidification of undercooled oxide and metallic eutectic melts[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2004(0):528-533. |
| [15] | LI M J;NAGASHIO K;ISHIKAWA T et al.Microstructure formation and in situ phase identification from undercooled Co61.8at％Si melts solidified on an electromagnetic levitator and an electrostatic levitator[J].Acta Materialia,2008,56:2514-2525. |
| [16] | Lu ZP.;Ng SC.;Li Y. .Reduced glass transition temperature and glass forming ability of bulk glass forming alloys[J].Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites,2000(1/3):103-114. |
| [17] | 王海燕,刘日平,马明臻,景勤,李工,孙力玲,王文魁.Fe-Si合金在落管中无容器凝固的组织形成规律[J].中国科学G辑,2005(04):399-407. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%