Ultra-precision dicing and wire sawing of silicon carbide (SiC)

2011 ◽  
Vol 88 (8) ◽  
pp. 2500-2504 ◽  
Author(s):  
S. Cvetković ◽  
C. Morsbach ◽  
L. Rissing
Keyword(s):  
Silicon Carbide ◽  
Ultra Precision

Ultra-precision manufacturing of silicon carbide mirrors with additive manufacturing

2021 ◽  
Author(s):  
Chao Xu ◽  
Hao Hu ◽  
Xiaoqiang Peng ◽  
Tao Lai ◽  
Jiahui Bao
Keyword(s):  
Silicon Carbide ◽  
Additive Manufacturing ◽  
Precision Manufacturing ◽  
Ultra Precision

A Study of Computer Controlled Ultra-Precision Polishing of Silicon Carbide Reflecting Lenses for Enhancing Surface Roughness

2014 ◽  
Vol 625 ◽  
pp. 437-445 ◽  
Author(s):  
Zhuo Lin Li ◽  
Wing Bun Lee ◽  
Benny C.F. Cheung ◽  
L.T. Ho ◽  
Yue Gang Fu
Keyword(s):  
Surface Roughness ◽  
Silicon Carbide ◽  
Optical Quality ◽  
Optical Systems ◽  
Space Telescopes ◽  
Large Space ◽  
High Optical Quality ◽  
Ultra Precision ◽  
Important Means ◽  
Computer Controlled

Reflecting lens is an important component of optical systems, such as high-resolution cameras, large space telescopes and meteorological satellites etc. Among the lens materials, Silicon Carbide (SiC) has attracted a lot of attention as an important optical material because of its excellent mechanical and physical properties. Apart from the form accuracy, the attainment of a consistently high optical quality in polishing SiC is still of a concern. There are advanced ultra-precision polishing machines that can correct geometrical errors and surface finish of the workpiece. These include surface roughness and waviness. However, the hardness of SiC material itself put an challenge for polishing process. In this paper, A computer controlled ultra-precision polishing (CCUP) method based on mechanical polishing is used to produce the SiC lens. Experiments are being designed on a 7-axis ultra precision polishing machine (Zeeko IRP200). As it is difficult to find out slurry which is harder than SiC so that the conventional polishing slurry is be used. It provides a nice consequence that it also efficient when the polish powder is softer than the machined materials. The tool pressure, polishing head speed and the feed rate are varied and optimized to obtain the best reflectivity of the lens being polished. A pilot experiment will be conducted for the corrective polishing for the form error of the optical surface made of SiC. The result from the study will provide an important means to optimize the process for machining SiC reflective lens using the CCUP process.

Molecular Dynamic Simulation of Micro-Structured Diamond Tool in Silicon Carbide Cutting

2020 ◽  
Author(s):  
Changlin Liu ◽  
Jianning Chu ◽  
Jinyang Ke ◽  
Xiao Chen ◽  
Jianguo Zhang ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Molecular Dynamic ◽  
Diamond Tool ◽  
Great Influence ◽  
Industrial Applications ◽  
Precision Machining ◽  
Dynamic Simulations ◽  
Wear Process ◽  
Ultra Precision ◽  
Micro Structures

Abstract Silicon carbide (SiC) is a material of great interest in many industrial applications. However, due to the hardness and brittleness nature, achieving ultra-precision machining of SiC is still challenging. In recent years, function surface with micro-structures has been introduced in cutting tool to suppress wear process. But the wear mechanism of the structured tool has not been revealed completely. Therefore, in present research, molecular dynamic simulations were conducted to investigate the influence of the micro-structure on the nano scale cutting process of 3C-SiC. The simulation results showed that the dislocation propagation in workpiece can be suppressed with a structured tool. The micro-structures have a great influence on the stress distribution in the workpiece subsurface. Furthermore, the abrasive wear of the structured tool is obvious smaller since the edges of the tool became blunt and the contact face between tool and workpiece changed to the close-packed plane of diamond. Moreover, the amorphization of the structured tool is effectively suppressed. This study contributes to the understanding of the details involved in the ultra-precision cutting of SiC.

Molecular Dynamic Simulation of Micro-Structured Diamond Tool in Silicon Carbide Cutting

2021 ◽  
Author(s):  
Liu Changglin ◽  
Jianning Chu ◽  
Jinyang Ke ◽  
Xiao Chen ◽  
Jianguo Zhang ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Molecular Dynamic ◽  
Diamond Tool ◽  
Industrial Applications ◽  
Material Behavior ◽  
Precision Machining ◽  
Dynamic Simulations ◽  
Wear Process ◽  
Ultra Precision ◽  
Micro Structures

Abstract Silicon carbide (SiC) is an important material in many industrial applications. However, due to the hardness and brittleness nature, achieving ultra-precision machining of SiC is still challenging. In recent years, function surface with micro-structures has been introduced in cutting tool to suppress wear process. But the wear mechanism of the structured tool has not been revealed completely. Therefore, in present research, molecular dynamic simulations were conducted to investigate the cutting performance of the micro-structure on the nano scale cutting process of 3C-SiC. The simulation results showed that the dislocation propagation in workpiece can be suppressed with a structured tool. The micro-structures have a significant influence on the stress distribution in the workpiece subsurface. Furthermore, the abrasive wear of the structured tool is obvious smaller since the edges of the tool became blunt and the contact face between tool and workpiece changed to the close-packed plane of diamond. Moreover, the amorphization of the structured tool is effectively suppressed. This study contributes to the understanding of the material behavior involved in the ultra-precision cutting of SiC.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

Microstructural Evaluation of Silicon Carbide Whisker Reinforced Alumina Fabricated with Carbon-Coated Whiskers

1991 ◽  
Vol 49 ◽  
pp. 920-921
Author(s):  
K. B. Alexander ◽  
P. F. Becher
Keyword(s):  
Silicon Carbide ◽  
High Resolution Electron Microscopy ◽  
Ceramic Composites ◽  
Interface Debonding ◽  
Resolution Electron ◽  
Microstructural Evaluation ◽  
Carbon Coated ◽  
Electron Energy Loss ◽  
Interfacial Films ◽  
Debonding Process

The presence of interfacial films at the whisker-matrix interface can significantly influence the fracture toughness of ceramic composites. The film may alter the interface debonding process though changes in either the interfacial fracture energy or the residual stress at the interface. In addition, the films may affect the whisker pullout process through the frictional sliding coefficients or the extent of mechanical interlocking of the interface due to the whisker surface topography.Composites containing ACMC silicon carbide whiskers (SiCw) which had been coated with 5-10 nm of carbon and Tokai whiskers coated with 2 nm of carbon have been examined. High resolution electron microscopy (HREM) images of the interface were obtained with a JEOL 4000EX electron microscope. The whisker geometry used for HREM imaging is described in Reference 2. High spatial resolution (< 2-nm-diameter probe) parallel-collection electron energy loss spectroscopy (PEELS) measurements were obtained with a Philips EM400T/FEG microscope equipped with a Gatan Model 666 spectrometer.

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