Influence of Carbon Content on Ceramic Injection Molding of Reaction-Bonded Silicon Carbide

2016 ◽  
Vol 13 (5) ◽  
pp. 838-843 ◽  
Author(s):  
Zhao Zhang ◽  
Yujun Zhang ◽  
Hongyu Gong ◽  
Xue Guo ◽  
Yubai Zhang ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Injection Molding ◽  
Carbon Content ◽  
Ceramic Injection Molding

A Ceramic Tubular Probe For Online Substance Concentration Measurement, Manufactured By Ceramic Injection Molding

2012 ◽  
Vol 2012 (1) ◽  
pp. 000604-000608
Author(s):  
Matthias Hartmann ◽  
Bertram Schmidt
Keyword(s):  
Injection Molding ◽  
Zirconium Oxide ◽  
Large Scale ◽  
Low Cost ◽  
Tetragonal Zirconia ◽  
Scale Production ◽  
Ceramic Injection Molding ◽  
Substance Concentration ◽  
Sensor Effect ◽  
Concentration Measurements

The current research presents recent respective to the work development of a ceramic tubular probe for online substance concentration measurements. The aim was to develop a robust and acid-resistant sensor device, which can be easily included in existing procedural pipeline systems. To archive those goals a lot of factors had to be checked. For the substance concentration measurements a capacitive sensor effect was chosen. With this method even low substance concentrations down to one-tenth of a per cent can be indentified. For the package material zirconium oxide (tetragonal zirconia polycrystal – TZP) was used. Zirconium oxide is a technical ceramic which is wear-resistant, acid-resistant, has a low thermal conductivity, is electrically isolating and can be uses in a ceramic injection molding (CIM) process. In the phase of the sensor design process multiple geometries for the sensor effect and integration space for the evaluation electronics had to be considered. A standardized DN 10 DIN 32676 flanged joint was also added for an unproblematic connection to the pipelines. All these needed geometries had to be integrated into one ceramic element. As a result of these requirements a 3D CAD model of the sensor element was designed. The CAD-file has shown that there was only the CIM technology left to comprehend developed sensor geometry. CIM is a low cost process for large-scale production which is distinguished by high size accuracy. In the CIM process the material shrinkage, this is caused by the needed debindering and sintering steps, had to be considered. The developed ceramic tubular probe was successfully tested in multiple fluidic systems. It has left the test phase and is now ready for maturity phase.

Wide Bandgap Fluorinated Silicon-Carbide-Nitride Films Using NF3

1991 ◽  
Vol 219 ◽  
Author(s):  
H. C. Goh ◽  
S. M. Tan ◽  
H. A. Naseem ◽  
S. S. Ang ◽  
W. D. Brown
Keyword(s):  
Silicon Carbide ◽  
Refractive Index ◽  
Carbon Content ◽  
Power Density ◽  
Deposition Rate ◽  
Gas Flow ◽  
Substantial Reduction ◽  
Wide Bandgap ◽  
Amorphous Hydrogenated Silicon ◽  
Stainless Steel Reactor

ABSTRACTAmorphous hydrogenated silicon carbide has been studied extensively because of its properties as a wide bandgap material. However, a large amount of methane is needed to deposit the material. Also, the high carbon content of these films poses some problems. The addition of NF3 to the gas stream results in wide bandgap films with a substantial reduction in the required CH4 flow for deposition. Amorphous SiCx Ny :H:F films were prepared using rf glow discharge decomposition of silane, methane, and nitrogen trifluoride in a parallel-plate stainless steel reactor. Gas flow rate and power density were varied. For a gas mixture containing 6% NF3 and 78% CH4, FTIR measurements reveal a reduction in C-H peak heights at 2960 cm-1 and 2880 cm-1 with respect to the Si-H peak at 2080 cm-1 indicating a smaller carbon content in the film. The C-H peaks shift to higher wavenumbers with increasing NF3. The use of NF3 increases the bandgap from 2.6 to 3.14 eV while reducing the refractive index from 2.12. to 1.87. A maximum deposition rate of 625 A/min was achieved. This should be compared to the very low deposition rate of 18 A/min for comparable bandgap Si-C films deposited using 97% methane in silane. Increasing the deposition power density resulted in a larger bandgap and a smaller refractive index.

scholarly journals PVB/PEG-Based Feedstocks for Injection Molding of Alumina Microreactor Components

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1219 ◽  
Author(s):  
Anna Julia Medesi ◽  
Dorit Nötzel ◽  
Thomas Hanemann
Keyword(s):  
Injection Molding ◽  
Large Scale ◽  
Metal Oxide Nanoparticles ◽  
Reaction Medium ◽  
Cost Effective ◽  
Polyvinyl Butyral ◽  
Shear Stresses ◽  
Scale Production ◽  
Ceramic Injection Molding ◽  
Functional Components

The ceramic injection molding (CIM) process is a cost-effective powder-based near net shape manufacturing process for large-scale production of complex-shaped ceramic functional components. This paper presents the rheological analysis of environmentally friendly CIM feedstock formulations based on the binder components polyvinyl butyral (PVB) and polyethylene gycol (PEG). The prepared PVB/PEG-based alumina molding compounds were investigated with respect to their PVB:PEG ratios as well as to their powder filling degrees in the range between 50 and 64 vol.%. Corresponding viscosities and shear stresses were determined for increasing shear rates to show the effects of increased PEG content and solid loadings on them. Two single reactor components were injection molded and subsequently joined in their green state for fabrication of an alumina microreactor. The intended purpose of the alumina microreactors is their potential application as wear-resistant and hydrothermal stable multifunctional devices (µ-mixer, µ-reactor, µ-analyzer) for continuous hydrothermal synthesis (CHTS) of metal oxide nanoparticles in supercritical water (sc-H2O) as the reaction medium.

Simulation of Ceramic Injection Molding for Zirconia Optical Ferrule

2007 ◽  
Vol 336-338 ◽  
pp. 997-1000 ◽  
Author(s):  
Mei Min Zhang ◽  
Bin Lin
Keyword(s):  
Injection Molding ◽  
Injection Molding Process ◽  
Molding Process ◽  
Melt Temperature ◽  
Ceramic Injection Molding ◽  
Rectangular Distribution ◽  
Simulation Results ◽  
Die Temperature ◽  
Ram Speed ◽  
Short Shot

Zirconia Ferrule is a key part for manufacturing fiber connectors. The ceramic injection molding (CIM) process of the optical ferrule was simulated with the commercial CAE software moldflow. In order to obtain the optimum results, the orthogonal method was introduced to discuss the influence of each parameter such as die temperature, melt temperature, ram speed and gate dimension with the two kinds of distribution layout system respectively. The simulation results show that the curved distribution runner system is more suitable than the rectangular distribution one in the optical ferrule molding. Moreover, the effect of gravity on the ceramic injection molding process was discussed for determining a more reasonable balanced runner system of the special designed two-plate mold with six die cavities. It was found that short shot occurred at the top of the die cavity while other five cavities were filled well in the original designed mold. And when the top die cavity’s round runner with section diameter of 4.0mm was increased to 4.17 mm, each cavity was balanced filled without short shot.

Aspects Concerning Rheological Properties of the CIM’s Binder Systems

2007 ◽  
Vol 23 ◽  
pp. 107-110
Author(s):  
Lidia Matrici ◽  
Şerban Domşa ◽  
Liviu Brânduşan
Keyword(s):  
Shear Stress ◽  
Injection Molding ◽  
Binder Content ◽  
Ceramic Injection Molding ◽  
Design Engineers ◽  
Low Viscosity ◽  
Injection Temperature ◽  
Production Problems ◽  
Plastic Injection ◽  
Independent Parameters

Ceramic Injection Molding (CIM) can provide design engineers with economic solution to otherwise apparently insoluble part production problems. CIM combine attributes of plastic injection molding with the higher properties of ceramics. The aim of the paper is examine the rheology of binder systems with independent parameters (shear rate, temperature, and binder content). The study also establish that the feedstocks used for CIM it must be assured an extremely low viscosity at the injection temperature. The experimental results show that an increasing of the wax contain with 5% leads to a more pronounced decrease of the shear stress than the increasing with 10 oC of the temperature. In all situations the temperature’s increasing determines a decrease of the feedstock’s viscosity and shear stress.

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