Effect of sol-gel processing parameters on structure of zirconia

The demand for high precision optical elements as micro lens arrays for displays increases continually. Economic mass production of such optical elements is done by replication with high precision optical molds. A new approach for manufacturing such molds was realized by diamond machinable and wear resistant sol-gel coatings. Crack free silica based hybrid coatings from base catalyzed sols from tetraethylorthosilicate (TEOS: Si(OC2H5)4) and methyltriethoxysilane (MTES: Si(CH3)(OC2H5)3) precursors were deposited onto pre-machined steel molds by spin coating process followed by a heat treatment at temperatures up to 800°C. Crack-free multilayer coatings with a total thickness of up to 18 µm were achieved. Micro-machining of these coatings was accomplished by high precision fly cutting with diamond tools. Molds with micro-structured coatings were successfully tested for injection molding of PMMA optical components. The wear resistance of the coatings was successfully tested by injection molding of 1000 PMMA lenses. Hardness and elastic modulus of the coatings were measured by nano indentation. The chemical composition was measured by X-ray photo electron spectroscopy (XPS) as a function of the sol-gel processing parameters.

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Effect of sol-gel processing parameters on thermal properties of silica aerogels

Materials Chemistry and Physics ◽

10.1016/s0254-0584(96)01924-4 ◽

1997 ◽

Vol 49 (2) ◽

pp. 129-134 ◽

Cited By ~ 23

Author(s):

D. Haranath ◽

G.M. Pajonk ◽

P.B. Wagh ◽

A. Venkateswara Rao

Keyword(s):

Thermal Properties ◽

Sol Gel ◽

Processing Parameters ◽

Silica Aerogels ◽

Gel Processing

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Effects of Sol–Gel Processing Parameters and Substrates on Crystallization of Potassium Tantalate–Niobate Thin Films

phys stat sol (a) ◽

10.1002/1521-396x(199709)163:1<67::aid-pssa67>3.0.co;2-o ◽

1997 ◽

Vol 163 (1) ◽

pp. 67-72 ◽

Cited By ~ 21

Author(s):

Dinghua Bao ◽

Anxiang Kuang ◽

Haoshuang Gu

Keyword(s):

Thin Films ◽

Sol Gel ◽

Processing Parameters ◽

Potassium Tantalate ◽

Potassium Tantalate Niobate ◽

Gel Processing

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Microwave processing CaO-Al203-SiO2 Glass Using Sol-Gel Technique

MRS Proceedings ◽

10.1557/proc-430-131 ◽

1996 ◽

Vol 430 ◽

Cited By ~ 1

Author(s):

Y. Zhou ◽

O. Van der Biest ◽

C. Groffils ◽

P. J. Luypaert

Keyword(s):

Power Level ◽

Sol Gel ◽

Structural Evolution ◽

Single Mode ◽

Processing Parameters ◽

Incident Power ◽

Sio2 Glass ◽

Gel Technique ◽

Microwave Applicator ◽

Gel Processing

AbstractGels in the CaO-A12O3-SiO2 (CAS) system were successfully converted into glass in a single mode, tuneable, cylindrical microwave applicator, operating at 2.45 GHz in the TM012 mode. Transparent glasses were formed as a result of the direct microwave heating of homogeneous CAS gels to well above their melting temperature (1170°C). The effect of processing parameters, such as incident power level, sample mass and location, and thermal insulation has been investigated. The excellent coupling of the CAS gel with microwave can be understood from the structural evolution during sol-gel processing.

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