optimum production of mirror with silicon carbide for the

SIC mirrors polishing - SPIE Digital Library

Silicon Carbide is a material of high interest in the design and manufacturing of space telescopes, thanks to its mechanical and thermal properties. Since many years, Reosc has gathered a large experience in the polishing, testing, integration and coating of large size Silicon Carbide mirrors as well as in the integration of full SiC TMAs.

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used to fabrie a 25-cm-diameterSiC mirror in a production furnace. The diameter of the mirror was reduced from 40-cmto 25-cecause (i) it was more compatible with toolings and fixtures in our 0.5-m-diafurnace and (ii)all the importantfeatures ofthe CVD

PROCESSING OF SILICON CARBIDE BY LASER MICRO SINTERING …

Silicon carbide – a solid with covalent bonds - is conventionally synthesized via the Acheson process. Usually solid bodies of silicon carbide with definite shapes are generated from the grained material via hot isostatic pressing or liquid phase sintering. Both

RU2692921C1 - Method of making mirror substrate of …

Method of making a mirror substrate from silicon carbide ceramic includes forming a workpiece of a substrate, heat treatment of the workpiece and subsequent impregnation of the workpiece with molten silicon, mixture for molding a workpiece contains a mixture

Evaluation of CVD silicon carbide for synchrotron …

Chemical vapor deposited silicon carbide (CVD SiC) is a recent addition to the list of materials suitable for use in the harsh environment of synchrotron radiation (SR) beam lines. SR mirrors for use at normal incidence must be ultrahigh vacuum compatible, must withstand intense x-ray irradiation without surface damage, must be capable of being

Silicon Carbide Optical Telescopes in ''Small Satellite'' Constellations

Silicon Carbide (Sic) has been space-proven in "large 1 Aperture Optical Sciences Inc., Durham, CT 06422 3. Process Baseline Baseline Sic Mirror Process th e We have analyzed Sic mirror production costs satellite" programs for both optical and structural

US4131697A - Method of coating carbon filaments with …

Carbon filaments having a coating of silicon carbide up to 0.2 micron or over 10 microns thick are described. A coating of silicon carbide is formed on carbon filaments by passing the heated filaments into an atmosphere of hydrogen and silicon tetrachloride to deposit silicon, and then into a silicon carbide-forming atmosphere.

Automated, reliable lapping and polishing systems make light work of hard silicon carbide …

allows users to generate a super-flat, mirror-like surface with atomic-scale roughness. The process is typically undertaken using the rotary or orbital motion of a chemical slurry between the wafer and a polishing plate. In both lapping and polishing, a fundamental

Fabriing Large-scale Mirrors Using Reaction-bonded …

2016/8/11· Nonetheless, in recent years, developers around the world have been honing silicon carbide mirror manufacturing technologies to enable the production of large-scale silicon carbide mirrors for use in telescopes.1–4For example, the 3.5m-diameter primary mirror of the Herschel Space Observatory was fabried in this way.

Silicon Carbide (SiSiC/SSiC)

Properties of Silicon Carbide (SSiC / SiSiC) Low density (3.07 to 3.15 g/cm 3) High hardness (HV10 ≥ 22 GPa) High Young’s modulus (380 to 430 MPa) High thermal conductivity (120 to 200 W/mK) Low coefficient of linear expansion (3.6 to 4.1x10 -6 /K at 20 to 400°C) Maximum operating temperature of SSiC under inert gas: 1,800°C.

Optimum structural design of lightweight silicon carbide …

Major efforts in space optics have inspired research in high performance, low cost, very lightweight reflective telescope systems in which Cassegrain system is widely used. Silicon carbide which has unique coination of attributes is used as the primary mirror material in this paper. According to the design requirement and processing technique of the mirror, and analyzing the effect of the

Experimental investigation into the selective laser …

2004/10/1· This paper presents an experimental investigation into the production of particulate silicon carbide (SiC) polyamide matrix composites via the selective laser sintering (SLS) process. FEPA standard F240 SiC grit was blended with Duraform polyamide to produce a powder blend composition of 50 wt% SiC for direct SLS processing.

Effect of technological parameters on densifiion of …

2018/12/1· Silicon carbide powder and thermoplastic binder on the base of paraffin wax and beeswax were mixed for 6 h and casted into the mold. All the specimens were disk-shaped with a diameter of 200 mm and thickness of 10 mm.

A Study of the Mirror-Like Grinding of Sintered Carbide …

1999/8/29· An optimum in-processs electrolytic dressing system was constructed, and the character- istics of mirror-like grinding of sintered carbide with it were 1. Introduction studied. In recent years developments in the metallic mould and elec- tronics industry have brought a rapid increase in the use of brittle materials such as hardened steel, ferrite and sintered 2.

Preparation of nano-sized silicon carbide powder using …

Nano-sized silicon carbide (SiC) powder was prepared by thermal plasma process using silicon tetrachloride (SiCl4) and methane (CH4). The synthesized powder was characterized by X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy and particle size analyzer. The powder was dominated by β-SiC including some of α-SiC and free carbon

Optimum design of lightweight silicon carbide mirror …

2008/6/15· According to the design requirement and on the basis of the principle that the thermal expansion coeffi cient of the support structure should match with that of the mirror, a lightweight silicon carbide primary mirror assely was designed. Finite element analysis coined with the parameter-optimized method was used during the design. Lightweight cell and rigid rib structure were used for …

Shape Adaptive Grinding of CVD Silicon Carbide on Graphite for X-Ray Mirror …

Shape Adaptive Grinding of CVD Silicon Carbide on Graphite for X-Ray Mirror Molding Dies Yoshiharu Naa, Anthony Beaucamp Richard Freeman (Zeeko Ltd.) Producing X-ray imaging telescopes is a very expensive endeavor, due in large

Changchun Institute of Optics,Fine Mechanies and …

Fabriing large-scale mirrors using reaction-bonded silicon carbide. One of the most effective methods of improving telescope resolution is to increase the diameter of the primary mirror. It is challenging, however, to fabrie very large diameters with complex surface shapes. For example, milling and polishing of the mirror surfaces can take

FINAL REPORT - NOAO

Final Report NOAO Feasibility Study – Production Report 01 Oct 204 Executive Summary SSG Precision Optronics, Inc. has completed a feasibility study for production of meter class Silicon Carbide mirror substrates for the Thirty Meter Telescope. The study

Additive Manufacturing of Silicon Carbide Mirrors | …

The ability to print near-net shapes in silicon carbide will increase design freedom and reduce production cost/time. This research will therefore have significant impact for space exploration.This development effort will generate new knowledge about the additive manufacturing of silicon carbide and enable the production of silicon carbide mirrors.

Silicon Carbide Mirror Substrates | Poco Graphite Inc., …

2020/2/21· Supersic, Poco Graphite’s high-performance silicon carbide, is an ideal material for fabriing mirror substrates. Mirrors built from Supersic substr This Week in Photonics All Things Photonics Podcast Photonics Spectra Newsletter BioPhotonics Newsletter

Development of the SOFIA silicon carbide secondary …

2003/3/3· This leads to select SIlicon Carbide for the mirror blank. Its development has been run by the ASTRIUM/BOOSTEC joint venture SiCSPACE, taking full benefit of the instrinsic properties of the BOOSTEC SiC-100 sintered material, associated to qualified processes specifically developed for space borne mirrors by ASTRIUM.

RU2692921C1 - Method of making mirror substrate of …

Method of making a mirror substrate from silicon carbide ceramic includes forming a workpiece of a substrate, heat treatment of the workpiece and subsequent impregnation of the workpiece with

US Patent Appliion for PRODUCTION OF SOLAR …

The invention relates to a complete method for producing pure silicon that is suitable for use as solar-grade silicon, comprising the reduction of a silicon oxide, purified by acidic precipitation from an aqueous solution of a silicon oxide dissolved in an aqueous

Silicon Carbide in Microsystem Technology — Thin …

2017/10/7· A film of cubic silicon carbide is epitaxially grown on a silicon wafer, and silicon oxide is deposited on this SiC layer. The two wafer oxide surfaces are treated and bonded together, then the handle wafer is protected and the silicon is removed from the …

Optimum structural design of lightweight silicon carbide …

Major efforts in space optics have inspired research in high performance, low cost, very lightweight reflective telescope systems in which Cassegrain system is widely used. Silicon carbide which has unique coination of attributes is used as the primary mirror material in this paper. According to the design requirement and processing technique of the mirror, and analyzing the effect of the

Shape Adaptive Grinding of CVD Silicon Carbide on Graphite for X …

pucks coated with 100um thick CVD silicon carbide, prepared in industry. The range of parameters included usage of resin and nickel for the pellet material, diamond grit sizes ranging from 3 to 40 µm diameter, SAG tool radius ranging from 10 to 40 mm, and

Preparation of nano-sized silicon carbide powder using …

Nano-sized silicon carbide (SiC) powder was prepared by thermal plasma process using silicon tetrachloride (SiCl4) and methane (CH4). The synthesized powder was characterized by X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopy, FT-IR spectroscopy and particle size analyzer. The powder was dominated by β-SiC including some of α-SiC and free carbon

Status of mirror segment production for the Giant Magellan …

icon carbide. m comes into ature gradien t ds to shift the uniform supp e mirror. The s the mirror. Th egment. The a n it of 690 kPa (gment include e with 36 ste olished, the s ture, shown i ll be modified, as well as a ns. ut 30 cm abo inner edge o f rnace was ope

Ion beam milling of silicon carbide optical components …

1993/11/1· The U.S. Department of Energy''s Office of Scientific and Technical Information OSTI.GOV Conference: Ion beam milling of silicon carbide optical components