Silicon carbonitride (SiCN) coatings were deposited on silicon and tungsten carbide substrates by co-sputtering silicon and carbon in argon and nitrogen mixture atmosphere using magnetron-sputtering system. The effect...Silicon carbonitride (SiCN) coatings were deposited on silicon and tungsten carbide substrates by co-sputtering silicon and carbon in argon and nitrogen mixture atmosphere using magnetron-sputtering system. The effect of the N2 concentration, RF substrate bias voltage and target current on film deposition rate, roughness, adhesion, mechanical and tribological properties of coatings were investigated. The deposition rate was found to increase with the increasing nitrogen concentration. X-ray photoelectron spectroscopy analysis showed that high nitrogen concentration in the nitrogen-argon gas mixture enhanced the incorporation of C and N but reduced the incorporation of Si. SiCN coatings have good tribological properties at a N2 concentration of approximately 60%.展开更多
Numerical study on dynamic hydroelastic problems is usually rather complex due to the coupling of fluid and solid mechanics.Here,we demonstrate that the performance of a hydroelastic microfluidic oscillator can be ana...Numerical study on dynamic hydroelastic problems is usually rather complex due to the coupling of fluid and solid mechanics.Here,we demonstrate that the performance of a hydroelastic microfluidic oscillator can be analyzed using a simple equivalent circuit model.Previous studies reveal that its transition from the steady state to the oscillation state follows the negative-differential-resistance(NDR)mechanism.The performance is mainly determined by a bias fluidic resistor,and a pressurevariant resistor which further relates to the bending stiffness of the elastic diaphragm and the depth of the oscillation chamber.In this work,a numerical study is conducted to examine the effects of key design factors on the device robustness,the applicable fluid viscosity,the flow rate,and the transition pressure.The underlying physics is interpreted,providing a new perspective on hydroelastic oscillation problems.Relevant findings also provide design guidelines of the NDR fluidic oscillator.展开更多
文摘Silicon carbonitride (SiCN) coatings were deposited on silicon and tungsten carbide substrates by co-sputtering silicon and carbon in argon and nitrogen mixture atmosphere using magnetron-sputtering system. The effect of the N2 concentration, RF substrate bias voltage and target current on film deposition rate, roughness, adhesion, mechanical and tribological properties of coatings were investigated. The deposition rate was found to increase with the increasing nitrogen concentration. X-ray photoelectron spectroscopy analysis showed that high nitrogen concentration in the nitrogen-argon gas mixture enhanced the incorporation of C and N but reduced the incorporation of Si. SiCN coatings have good tribological properties at a N2 concentration of approximately 60%.
基金the National Natural Science Foundation of China(No.51575282)the Fundamental Research Funds for the Central Universities(Nos.30915118803 and 30916012101)+1 种基金Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX200266)Nanyang Technological University and Singapore Institute of Manufacturing Technology,under the Agency for Science,Technology and Research(A*STAR,Singapore).
文摘Numerical study on dynamic hydroelastic problems is usually rather complex due to the coupling of fluid and solid mechanics.Here,we demonstrate that the performance of a hydroelastic microfluidic oscillator can be analyzed using a simple equivalent circuit model.Previous studies reveal that its transition from the steady state to the oscillation state follows the negative-differential-resistance(NDR)mechanism.The performance is mainly determined by a bias fluidic resistor,and a pressurevariant resistor which further relates to the bending stiffness of the elastic diaphragm and the depth of the oscillation chamber.In this work,a numerical study is conducted to examine the effects of key design factors on the device robustness,the applicable fluid viscosity,the flow rate,and the transition pressure.The underlying physics is interpreted,providing a new perspective on hydroelastic oscillation problems.Relevant findings also provide design guidelines of the NDR fluidic oscillator.
