Papers by Keyword: Deposition Rate

Abstract: The deposition rate is a critical parameter that has a significant influence in Wire Arc Additive Manufacturing (WAAM) of critical aerospace components made of AISI 410 Stainless steel. In this work, Taguchi parametric modeling for wire arc additive manufacturing is carried out using the input parameters of the welding current (WC), the travel speed of the nozzle (TSN), and the distance between the nozzle and the workpiece (DNW). Each factor is varied at 3 levels and the experiments are carried out based on Taguchi L9 orthogonal array. The response variable considered is the deposition rate (DR). Based on the results from experiments, the optimal combination of process parameters obtained is 140 A of welding current, 3mm/s of the travel speed of the nozzle, and 15 mm of distance between the nozzle and workpiece. The optimum deposition rate achieved is 8.545 g/s. The percentage of contribution of various factors is found to be TSN at 43.65% and WC at 16.6% and DNW at 4.9%.

Abstract: The DC magnetron sputtering is often used for fabricating thin hard coatings for a wide range of industrial applications. The technique allows using DC power for deposition low or non-conductive films from metal target without using expensive RF power for insulation target. However, the performance of DC reactive sputtering is affected significantly by a phenomenon namely target poisoning. When the target poisoning occurs, coating is formed not only on substrate surface but also on target surface, which results in the reduction of deposition rate and coating properties. This paper presents a study on poisoning of Ti target during TiN coating deposition in the Ar + N₂ atmosphere. Results showed that the target poisoning state is impressed dramatically by partial pressure and flow rate of nitrogen gas. In poisoning mode, the deposition rate was reduced significantly compared to that in the metal mode. In addition, the formed TiN coating exhibited a non-stoichiometric and low adhesion to the substrate.

Abstract: The Fe nanowire arrays are prepared by the method of alternating current, constant voltage and constant current respectively. the morphology and composition of the Fe nanowires have been characterized By scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDS). The Fe nanowires growth rate with different current density was studied in anodic aluminum oxide (AAO) template for pore diameter of 85 nm, pore depth of 55 μm under the same total charge. Research shows that the deposition rate of nanowires first slightly decreased, dramatically increased again and then reduced greatly with the increase of current density from 1 mA/cm² ~ 5 mA/cm².

Abstract: A new processing concept has been developed to produce Ni-P-PTFE electroless composite coating. This method combines magnetic field and electroless composite plating techniques to prepare high-quality Ni-P-PTFE electroless composite coating. The influence of magnetic on composite plating process and coatings performance by changing some factors such as the plating time, magnetic field strength, magnetic field direction. The results indicate that the external magnetic field improved deposition rate and the PTFE particles content of composite coatings, meanwhile, some performances of composite coating like thickness, corrosion resistance, were effected by external magnetic field strength. Therefore, the method combines magnetic field and electroless completing techniques had a wide application prospect in the aspect of improving the properties of electroless composite coating.

Abstract: 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.

Abstract: Complexing agent in the electroless nickel coating (Ni-P) solution plays an important role to maintain the coating deposition rate during the coating process. This paper studies the effect of two complexing agent; sodium citrate and sodium acetate in Ni-P coating. Ni-P coating was prepared in bath containing: NiSO4·6H2O, NaPO2H2·H2O, C2H5NO2, and Pb (NO3)2. Ni-P coating was coated on polished Cu substrate. Morphology, thickness and surface roughness of Ni-P coating were characterized using scanning electron microscope (SEM)/electron dispersive x-ray (EDX), optical microscope (OM), and atomic force microscopy (AFM). The result showed that sodium acetate have higher deposition rate up to 12 μm/h, whereas sodium citrate provided better surface morphology with lower surface roughness.

Abstract: In this paper, electroless Ni-P-Al₂O₃ coatings have been synthesized on mild steel shaft by adding various concentration of cetyltrimethyle ammonium bromide (CTAB) into plating baths. Compared with Polyvinyl pyrrolidone (PVPk30), cationic surfactant CTAB shows better effect in dispersing the Al₂O₃ particles. With the increasing of CTAB concentration in the plating baths, dispersion of Al₂O₃ particles in the Ni-P-Al₂O₃ coatings was improved due to high electrostatic repulsive force between Al₂O₃ particles and CTAB molecular, whereas deposition rate of the Ni-P-Al₂O₃ coatings was decreased.

Abstract: Three-dimensional printing technology based on deterministic electrochemical deposition method has been developed, which is generated from the electroplating. The traditional electroplating system has been improved to ensure the printing process controllable. Through accurate control of the deposition region, deposition rate, and the dwelling time in the printing process, a three-dimensional object of almost any shape can be obtained by deterministic manufacturing process. Through addition of alcohol to the electrolyte, Marangoni effect is generated, which will improve the property of the deposited layer. The deterministic electrochemical deposition not only can decrease the cost of the printing process, but also will promote the application of the 3D printing technique in many fields.

Abstract: Through orthogonal test of Ni-P chemical plating process optimization to determine the optimum process recipe, the Ni-P-β-SiC composite coating were prepared by chemical plating method. The deposition rate, microhardness, composition and organization of Ni-P-β-SiC composite coating are observed and analyzed by scanning electron microscopy (SEM), vivtorinox microhardness tester, X ray diffraction (XRD) and energy spectrum analysis (EDS). The influences of β-SiC particle concentration in bath on the solution of composite coating deposition rate and microhardness. The results show that the influence of composite coating deposition rate and microhardness are NiSO₄•6H₂O, NaH₂PO₂•H₂O, C₃H₆O₃, and PH. The optimum process conditions: NiSO₄•6H₂O 25 g/L, NaH₂PO₂•H₂O 27 g/L, C₃H₆O₃ 27 ml/L, PH 5.2. It was found that the Ni-P-β-SiC composite coating with 5g/L β-SiC particles exhibited a maximum deposition rate and microhardness, the deposition rate of composite coating is 12.32μm/h, microhardness is 567.93HV_0.05.

Abstract: In order to improve the non-cyanide electroless gold plating deposition performance, the effects of the kinds of additives as well as its concentration on the deposition performance were investigated. The appearance inspection, deposition rate, adhesive force, surface morphology and corrosion resistance were evaluated. The results showed that the introduction of appropriate additives did improve the coating properties. The optimal concentration of polyethylene glycol and polycrylamide were 0.6~1.0 g·L^-1 and 1.0~1.5 g·L^-1, respectively. The corrosion resistance of the coating deposited in baths containing polyacrylamide was best.