Diamond Machinable Sol-Gel Silica Based Hybrid Coatings for High Precision Optical Molds

2010 ◽  
Vol 438 ◽  
pp. 65-72 ◽  
Author(s):  
Andreas Mehner ◽  
Ju An Dong ◽  
Timo Hoja ◽  
Torsten Prenzel ◽  
Yildirim Mutlugünes ◽  
...  
Keyword(s):  
Injection Molding ◽  
High Precision ◽  
Sol Gel ◽  
Processing Parameters ◽  
Hybrid Coatings ◽  
Optical Elements ◽  
Optical Components ◽  
New Approach ◽  
Free Silica ◽  
Gel Processing

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.

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

1997 ◽  
Vol 49 (2) ◽  
pp. 129-134 ◽  
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

A process for shaping high-precision optical components for ground- and space-based electrooptic systems

2019 ◽  
pp. 77-88
Author(s):  
Vladimir A. GORSHKOV ◽  
Alexey S. SAVELYEV ◽  
Artem S. NEVROV ◽  
Aleksandra V. SMIRNOVA
Keyword(s):  
Standard Deviation ◽  
High Precision ◽  
Surface Shape ◽  
Optical Systems ◽  
Optical Elements ◽  
Optical Components ◽  
Earth Remote Sensing ◽  
Aspheric Surfaces ◽  
Shape Precision ◽  
Surface Shaping

The paper reviews advanced process for manufacturing high-precision optical components used in space-based electrooptic systems for scientific research and Earth remote sensing. It presents an integrated process for automatic shaping (TESAF) of aspheric surfaces, including off-axis surfaces, of optical elements for electrooptic systems. This paper discusses various methods for shaping optical parts with virtually any degree of asphericity and various values of the off-axis parameter (off-axis aspherics) achieving surface shape precision to within λ/60…λ/80 (λ = 0.6328 micron) by the standard deviation criteria. The paper also presents the newly developed off-axis collimators, designed to shape a reference wavefront within a broad spectral range from ultraviolet to infrared radiation. In particular, a mirror collimator with an adaptive off-axis mirror that is capable of changing the wavefront that is being formed in order to obtain the response function of the electrooptical system under study. Optical systems built using the TESAF process are already successfully used. Key words: surface shaping, aspheric surface, surface interferogram, standard deviation.

Non-Hydrolyzed Resins for Organic-Inorganic Hybrid Coatings

2017 ◽  
pp. 771-801 ◽  
Author(s):  
Stefan Holberg
Keyword(s):  
Protective Coatings ◽  
Sol Gel ◽  
Hybrid Coatings ◽  
Industrial Scale ◽  
Atmospheric Moisture ◽  
Inorganic Hybrid ◽  
Chemical Structures ◽  
Hydrolysis And Condensation ◽  
Gel Processing ◽  
Area Of Application

This chapter focuses on resins based on non-hydrolyzed, monomeric and polymeric alkoxysilanes. As alternative to classical sol-gel processing, the resins are applied to a surface without a preceding hydrolysis step. Only after application, hydrolysis and condensation of the alkoxysilyl groups occur by means of atmospheric moisture to result cross-linked organic-inorganic hybrid coatings. While the use of non-hydrolyzed silanes is well established, for example by applying polyethyl silicate as binder for zinc-rich anti-corrosive primers, this chapter describes the chemical structures of various novel organic-inorganic hybrid precursors that have significantly extended the area of application to adhesives and scratch-resistant, repellent, or anti-fouling coatings. At present, individual resins are produced and applied at industrial scale in the fields of protective coatings and automotive topcoats.

scholarly journals Effect of sol-gel processing parameters on structure of zirconia

Cerâmica ◽  
2019 ◽  
Vol 65 (suppl 1) ◽  
pp. 17-21 ◽  
Author(s):  
D. G. da Silva ◽  
W. L. Vasconcelos
Keyword(s):  
Sol Gel ◽  
Processing Parameters ◽  
Gel Processing

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

1996 ◽  
Vol 430 ◽  
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.

Correlation of sol–gel processing parameters with microstructure and properties of a ceramic product

2003 ◽  
Vol 50 (4-5) ◽  
pp. 325-337 ◽  
Author(s):  
Nopporn Thanabodeekij ◽  
Mathavee Sathupunya ◽  
Alexander M. Jamieson ◽  
Sujitra Wongkasemjit
Keyword(s):  
Sol Gel ◽  
Processing Parameters ◽  
Ceramic Product ◽  
Microstructure And Properties ◽  
Gel Processing
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