方石英

方石英含量对氧化物结合SiC材料性能的影响

Effect of Cristobalite Content on properties in silicon carbide material bound with oxide

1300℃时，不定形SiO2进一步结晶形成方石英。

Furthermore , when temperature approaching 1 300 ℃, amorphous SiO_2 was crystallized into cristobalite .

方石英形成于石英或鳞石英热力学稳定区是一种普遍的现象，并基本上是由非晶态SiO2转变而成。

The cristobalite , transformed from amorphous silica basically , is ubiquitous in the thermodynamic stable region of quartz or tridymite .

结果表明，Na的诱导作用使无定型氧化硅在焙烧过程中相变为α-方石英结构，同时伴有比表面积的大幅度下降；

The inducing effect of sodium makes amorphous silica transferred to α cristobalite during calcination , and the specific surface area decreases enormously as a consequence .

1500℃氧化后的表面氧化层中同时存在低温石英、方石英和非晶态SiO2。

There are low temperature quartz , cristobalite and amorphous silica in the surface oxidation layer after the oxidation at 1 500 ℃ .

X射线衍射显示：在985℃以下，硅酸铝纤维呈非晶结构，高于985℃时，析出莫来石和方石英，并定量计算出不同温度下硅酸铝纤维晶化的百分率。

The X ray diffraction revealed that , when the temperature is below 985 ℃, alumino silicate fibre was amorphous structure , but when heated to above 985 ℃, mullite and cristobalite were precipitated from alumino silicate fibre .

晶核剂TiO2对于促进方石英晶相析出的能力较差，且当玻璃中不含Al2O3时，TiO2的成核效果不明显，获得的晶粒较粗。

However , the nucleating agent TiO_2 cannot effectively promote the crystallization of the cristobalite crystallites and does not have obvious effects on the nucleation of Li_2O-ZnO-SiO_2 glass when there is no Al_2O_3 in the glass .

相组成分析表明，B2配方样品热震前后的主晶相均为a-SiC、红柱石、莫来石和方石英。

XRD analysis showed that both of the main phases in the samples of series B are a-SiC , andalusite , mullite and cristobalite before and after thermal shock .

结果表明：经1350℃煅烧72h，1450℃再煅烧3h的块状结晶石英岩，70%的石英已转化为微晶方石英。

The results show that for the bulk crystalline quartzite , sintered at 1 450 ℃ for 3 h after 1 350 ℃ for 72 h , the 70 % of quartz transforms into micro-crystalline cristobalite .

1430～1450℃经48～72h烧成未用的硅砖主相为鳞石英和方石英，并有少量残留石英。

The phase components of unused silica brick , which is sintered in 1 430 1 450 ℃ for 48 72 h , are mainly the tridymite and cristobalite with small amount of remainder quartz .

XRD图谱和SEM照片表明：石英和高岭石是这些粘土的主要矿物成分，它们经1250℃烧成后形成大量的莫来石和少量的α方石英，表明这些粘土适合用于生产建筑陶瓷；

Quartz and kaolinite are the predominant minerals with high mullite and α _ quartz formation at 1 250 ℃ as evidence from their XRD patterns and SEM photographs . The dominance of kaolinite and the high mullitization further justify the mineralogical suitability of these clays for building ceramics .

SiC颗粒在静态空气气氛中经1200℃×10h钝化氧化处理后在表面形成厚约0.6μm，具有晶态的β方石英结构的致密氧化膜。Air（初三适用）

The dense oxide film of about 0.6 μ m is formed on the surface of the SiC particles by passive oxidation , when the SiC particles were treated at 1200 ℃ for 10h in a stationary air ambient . The film was determined to be β cristobalite using XRD .

晶核剂P2O5在该系统玻璃中具有成核作用，并能促进方石英固溶体的析出，使微晶玻璃获得较好的力学性能（抗弯强度为133MPa，维氏硬度为638MPa）；

P_2O_5 has excellent ability of promoting the nucleation of the base glass and forming the cristobalite crystallites . The glass-ceramics containing the cristobalite crystallites has excellent mechanical properties with bend strength of 133 MPa and Vickers-hardness of 638 MPa .

实验表明高石英质瓷的相变温度在1100℃到1300℃，并且随着温度的升高形成了新的物相莫来石（3Al2O3·2SiO2）和方石英（SiO2）。

The experiment result shows that the transition temperature of high - . quartz porcelain is about 1100 ℃ to 1300 ℃ and with the increase in temperature , the flew phase formed is Mullite ( 3Al2O3 ' 2SiO2 ) and Cristobalite ( SiO2 ) .

硅砖中α-方石英的晶体结构与形貌

Crystal structure and morphology of α cristobalite in silica bricks

β方石英的振动光谱和方石英的相变

Vibrational spectrum of β cristobalite and phase transition of cristobalite

α-方石英强化日用瓷研制过程中几个关键问题分析

Key to study of α - cristobalite durable China

石英块料直接煅烧法生产方石英

Preparation of Cristobalite by Direct Calcination with Nubby Quartz

有序方石英矿非线性光学晶体的探索

Explore of Nonlinear Optical Crystals in Ordered Cristobalite Series

无定型氧化硅转变为α-方石英的振动光谱

Vibration Spectroscopy on Transformation of Amorphous Silica to-cristobalite

α&方石英强化瓷的研制

The Development of α - cristobalite Reinforced Porcelain

方石英转变及其在熔模铸造中的意义

Cristobalite Transformation and Its Role in Investment Casting

α方石英振动光谱的计算

Calculation of the vibrational spectrum of α cristobalite

硅基陶瓷型芯方石英含量与叶片浇注不露芯率的关系

Effects of Cristobalite Content of Silica Base Ceramics Core on the Rate of Qualified Pouring

α方石英的结晶形貌

On the morphology of α - cristobalite

影响定向空心叶片陶瓷型芯性能的一个重要因素&方石英含量的控制

Effect of Cristobalite Content on the Properties of Ceramic Core in Making Directionally Solidified Hollow Blade

由此提供了一组甚好的β方石英的力常数。

As a consequence a good set of the six valence force constants for β cristobalite is given .

析晶中主晶相类别尚未查清，次晶相确定为α－方石英。

The main crystalline of this system is not identified , while the accompanied crystalline is α - cristobalite .

焙烧达1150℃时，原组成无定形二氧化硅则晶化为α-方石英，除吉林土具有一级孔洞。

When roasted at 1150 ℃, the amorphous silica of which diatomite is composed crystallized into α - cristobalite .

方石英的亚稳态形成机制探讨本文介绍了一种从α-石英制取鳞石英和方石英的疗法和条件。

DISCUSSION ON METASTABLE FORMATION MECHANISM OF CRISTOBALITE 1 Preparation of tridymite and cristobalite from α - quartz was studied .