Effects of Acetylene on Deposition Rate of Stainless Steels Using Thermal Chemical Vapor Deposition

Author(s):  
M. Mostafizur Rahman ◽  
Shaon Talukdar ◽  
Mohammad Asaduzzaman Chowdhury ◽  
Rasel Khan ◽  
Abdullah A. Masum ◽  
...  

A hot filament thermal chemical vapor deposition (CVD) reactor was used to deposit solid thin films on stainless steel 316 (SS 316) and stainless steel 201 (SS 201) substrates at different flow rates of acetylene (C2H2) gas. The variation of thin film deposition rate with the variation of gas flow rate has been investigated experimentally. During experiments are conducted under gas flow rate (1-5) lit/min gas flow rate, duration of deposition (10-60 min), pressure (0.2-1 bar), average surface roughness (0.3-1.05) µm and temperature 800 °C considered. Experimental results show that deposition rate on SS 316 and SS 201 increases with the increase in gas flow rate. The deposition rate also shows increasing trend with pressure and duration of deposition. Under the above mentioned experimental conditions deposition is found to be maximum of SS-316 compared to SS-201. In relation to roughness the maximum deposition is found at 0.5 microns but comparing the both materials -316 and-201 highest of deposition rate is obtained from SS-316.

2015 ◽  
Vol 1109 ◽  
pp. 456-460
Author(s):  
Najwa Ezira Ahmed Azhar ◽  
Shafinaz Sobihana Shariffudin ◽  
Aimi Bazilah Rosli ◽  
A.K.S. Shafura ◽  
Mohamad Rusop

ZnO nanotetrapod with different oxygen flow rate was prepared by thermal chemical vapor deposition. We have successfully deposited ZnO nanotetrapod on synthesis Zn powder using double furnace with argon (Ar) and oxygen (O2) gas as source material. In this study, we report the effect of different gas flow rate (5 sccm to 15 sccm) on structural and optical properties of the ZnO nanotetrapod. The morphology of ZnO nanotetrapods were analyzed by field emission scanning electron microscope (FE-SEM). It exhibits the length of the nanotetrapods arm decrease with increased of flow rate and diameter of nanotetrapod in range 30 nm to 90 nm. The optical properties were determined through XRD and photoluminescence with 2θ (30o to 80o) and wavelength 350 nm to 620 nm respectively. PL spectra show that the UV emission centred at 380 nm while yellow-orange emission centred at 540 nm.


Author(s):  
Mohammad A. Chowdhury ◽  
Dewan M. Nuruzzaman ◽  
Mohammad L. Rahaman

Solid thin films have been deposited on carbon steel substrates in a chemical vapor deposition (CVD) reactor where natural gas, mostly methane (CH4), was used as a precursor gas. The effect of gas flow rate on the thin film deposition rate has been investigated experimentally. The effect of gap between activation heater and substrate on the deposition rate has also been observed. To do so, a hot filament thermal chemical vapor deposition unit is used. The flow rate of natural gas varies from 0.5 to 2 l/min at normal temperature and pressure (NTP) and the gap between activation heater and substrate varies from 4 to 6.5 mm. Results show that the deposition rate on carbon steel increases with the increase of gas flow rate. It is also seen that deposition rate increases with the decrease of gap between activation heater and substrate within the observed range. These results are analyzed by dimensional analysis to correlate the deposition rate with gas flow rate, surface roughness and film thickness. In addition, friction coefficient and wear rate of carbon steel sliding against SS 304 under different normal loads are also investigated before and after deposition. The obtained results reveal that in general, the values of friction coefficient and wear rate are lower after deposition than that of before deposition.


MRS Advances ◽  
2016 ◽  
Vol 2 (29) ◽  
pp. 1533-1538 ◽  
Author(s):  
S. Ishihara ◽  
Y. Hibino ◽  
N. Sawamoto ◽  
T. Ohashi ◽  
K. Matsuura ◽  
...  

ABSTRACTMolybdenum disulfide (MoS2) thin films were fabricated by two-step chemical vapor deposition (CVD) using (t-C4H9)2S2 and the effects of temperature, gas flow rate, and atmosphere on the formation were investigated in order to achieve high-speed low-temperature MoS2 film formation. From the results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) investigations, it was confirmed that c-axis orientation of the pre-deposited Mo film has a significant involvement in the crystal orientation after the reaction low temperature sulfurization annealing and we successfully obtained 3 nm c-axis oriented MoS2 thin film. From the S/Mo ratios in the films, it was revealed that the sulfurization reaction proceeds faster with increase in the sulfurization temperature and the gas flow rate. Moreover, the sulfurization under the H2 atmosphere promotes decomposition reaction of (t-C4H9)2S2, which were confirmed by XPS and density functional theory (DFT) simulation.


2012 ◽  
Vol 576 ◽  
pp. 594-597 ◽  
Author(s):  
Mohammad Asaduzzaman Chowdhury ◽  
Dewan Muhammad Nuruzzaman

A hot filament thermal chemical vapor deposition (CVD) reactor was used to deposit solid thin films on stainless steel 316 (SS 316) substrates at different flow rates of natural gas. The variation of thin film deposition rate with the variation of gas flow rate has been investigated experimentally. During experiment, the effect of gap between activation heater and substrate on the deposition rate has also been observed. Results show that deposition rate on SS 316 increases with the increase in gas flow rate. It is also observed that deposition rate increases with the decrease in gap between activation heater and substrate within the observed range. In addition, friction coefficient and wear rate of SS 316 sliding against SS 304 under different normal loads are also investigated before and after deposition. The experimental results reveal that improved friction coefficient and wear rate are obtained after deposition as compared to that of before deposition.


2007 ◽  
Vol 1057 ◽  
Author(s):  
Yoshiyuki Suda ◽  
Junichi Takayama ◽  
Takeshi Saito ◽  
Atsushi Okita ◽  
Junji Nakamura ◽  
...  

ABSTRACTWe report the effect of CO2 addition to CO4 gas on carbon nanotube (CNT) growth by chemical vapor deposition. CO2 gas was introduced during the growth of CNTs on Fe0.05Mo0.025MgO0.925 and Ni0.05Mo0.025MgO0.925 catalysts by CO4 gas at a temperature of 800–850°C, and its concentration in a fraction of the gas flow rate was varied from 5×10−3 to 50%. In the experimental condition of the preferential growth of multi-walled CNTs, the carbon yield and the G/D ratio in the Raman spectra of the CNTs grown in 10%-CO2/CO4 were slightly higher than that grown in CO4 only. However, CNTs hardly grew when the CO2 concentration was more than 10%. We then prepared CO2 gas diluted with Ar gas (CO2/Ar) and varied its flow rate between 0 and 10 sccm. As the CO2/Ar gas flow rate was increased, the number of RBM peaks decreased even though the G/D ratio gradually decreased. The decrease in the RBM intensities of CNTs on the FeMoMgO catalyst was more significant than that of NiMoMgO.


2010 ◽  
Vol 25 (9) ◽  
pp. 1778-1783 ◽  
Author(s):  
Seok-Hyo Yun ◽  
Suthan Kissinger ◽  
Don Wook Kim ◽  
Jun-Ho Cha ◽  
Yong-Ho Ra ◽  
...  

We demonstrated the growth of indium nitride (InN) nanowires on Si(111) substrates by metalorganic chemical vapor deposition without the use of any intermediate GaN or AlN buffer layer. The InN nanowires were grown by forming the Au + In droplets and In droplets on the Au- and In-coated Si substrate. The growth conditions such as chamber pressure, chamber temperature, reaction gas flow rate, and carrier gas flow rate were optimized to yield nanowires free from contamination. Depending on the growth parameters different growth regimes for the InN nanowires were identified. The strength of self-catalytic route has been highlighted. The morphology and microstructures of samples were characterized by x-ray diffraction and scanning electron microscopy (SEM). The transmission electron microscopy and SEM investigations showed that the InN nanowires are single crystals with diameters ranging from 40 to 400 nm, and lengths up to 3 µm. Photoluminescence spectra of the InN nanowires showed a strong broad emission peak at 0.77 eV.


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