外文翻譯---在萘-樟腦非水可升華的溶劑共晶體系下進行室溫冷凍干燥來制備陶瓷（英文）

1、See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/227709814Room-Temperature Freeze Casting for CeramicsWith Nonaqueous Sublimable Vehicles in theNaphthalene–Camp

2、hor Eutectic SystemARTICLE in JOURNAL OF THE AMERICAN CERAMIC SOCIETY · JANUARY 2005Impact Factor: 2.61 · DOI: 10.1111/j.1151-2916.2004.tb06353.xCITATIONS29READS1122 AUTHORS, INCLUDING:John W. HalloranUnivers

3、ity of Michigan236 PUBLICATIONS 3,599 CITATIONS SEE PROFILEAvailable from: John W. HalloranRetrieved on: 15 October 2015with 3 wt% dispersant (to 100 wt% Al2O3 powder), were prepared in 10–20 cm3 batches. During the

4、warm ball-milling process, the naphthalene vapor and the camphor vapor in the sealed bottle should be in equilib- rium with the slurry. Because the naphthalene vapor pressure and the camphor vapor pressure are different

5、and these vapors are lost when the bottle is opened, the naphthalene ratio to camphor in the warm ball-milled slurries will be changed from the initial charged ratio. As is explained in detail later, microstructural obse

6、rvation of solidified naphthalene–camphor alloys revealed that the initial charge of 40 wt% naphthalene–60 wt% camphor became the eutectic composition, which is 35 wt% naphthalene–65 wt% camphor according to the phase di

7、agram,16 after the warm ball- milling in this work. Initial charges of 56 wt% naphthalene–44 wt% camphor, 40 wt% naphthalene–60 wt% camphor, and 31 wt% naphthalene–69 wt% camphor were used as hypoeutectic, eutectic, and

8、hypereutectic vehicles, respectively. Measured liquid densities of hypoeutectic (56 wt% naphthalene–44 wt% camphor) and eutectic (40 wt% naphthalene–60 wt% camphor) composi- tions are both 0.983 g/cm3 at 55°C, and t

9、hat of hypereutectic (31 wt% naphthalene–69 wt% camphor) composition is 0.964 g/cm3at 60°C. Examples of the charged weight of each material for 48 vol% Al2O3 slurries are shown in Table II. Warm ball-milled slurries

10、 were poured into a cylindrical de- pression on the surface of polyurethane molds at room tempera- ture. The size of the mold was 10 mm in diameter and 5 mm in depth. The slurries solidified typically within 20 min to yi

11、eld solid rigid green bodies. After demolding, green bodies were placed in ambient atmosphere with an airflow rate of 0.01–0.05 m/s to sublime the frozen naphthalene–camphor alloy from the greenbodies. Judging from the w

12、eight change, this sublimation process typically finished in 60 h. During this freeze-drying process, neither crack formation nor measurable shrinkage was observed. After the freeze-drying process, the cast bodies were s

13、intered at 1600°C (ramping rate of 5°C/min) for 4 h without a special binder burnout process. The fabrication procedure described above is summarized in Fig. 2.(3) CharacterizationThe density of sintered bodies

14、 was measured using the water displacement method based on the Archimedean principle. The microstructure of the sintered bodies was observed with scanning electron microscopy (SEM; XL-30, Philips Electronics N.V., Eindeh

15、oven, The Netherlands). The microstructure of solidified naphthalene–camphor alloys was observed with optical micros- copy (OM; BH2-UMA, Olympus, Tokyo, Japan) in the transmis- sion mode by dropping molten liquid alloys

16、without ceramic powder and the dispersant onto a slide glass.III. Results and DiscussionFigure 3 shows the relative density of Al2O3 sintered bodies as a function of the charged solid content (Al2O3 volume fraction) inFi

17、g. 1. Naphthalene–camphor phase diagram.16 Fig. 2. Schematic chart of the fabrication procedure.Table I. Some Physical Properties of Naphthalene, Camphor, and WaterChemical formula Solidification temperature (°C) Vo

18、lume change during solidification Liquid viscosity (mPa?s) Vapor pressure in solids (Pa)Naphthalene C10H8 80 Negative 0.91 (80°C) 1.3 ? 102 (52°C) Camphor C10H16O 180 Negative 0.63 (180°C) 1.3 ? 102 (41

19、76;C) Water H2O 0 Positive 1.0 (20°C) 1.3 ? 102 (?20°C)Table II. Example of the Charged Weight for 48 vol% Al2O3 SlurriesNaphthalene-to-camphor ratio Al2O3 (g) Dispersant (g) Naphthalene (g) Camphor (g)Hypoeute

20、ctic 56 wt% N–44 wt% C 41.37 1.24 5.60 4.40 Eutectic 40 wt% N–60 wt% C 41.37 1.24 4.00 6.00 Hypereutectic 31 wt% N–69 wt% C 42.18 1.27 3.10 6.90November 2004 2015 Room-Temperature Freeze Casting for Ceramics with Nonaque