scholarly journals Influence of Spray Parameters on the Thickness, Hardness and Porosity of low-pressure Cold Sprayed WC-Ni Coatings

2021 ◽  
Author(s):  
Wania Jibran ◽  
James Hogan ◽  
André McDonald
Keyword(s):  
Coating Thickness ◽  
Feed Rate ◽  
Low Pressure ◽  
System Response ◽  
Influence Of Spray Parameters ◽  
Spray Parameters ◽  
Surface Porosity ◽  
Gas Temperature ◽  
Spray System ◽  
Coating Hardness

Abstract In this study, a 33 full factorial design methodology was used ­­to analyze the effects of spray parameters on the thickness, hardness, and surface porosity of low-pressure cold-sprayed WC-17Ni coatings. Three levels were selected for the spray parameters included in the design which were the powder feed rate (17.1 g/min, 21.1 g/min, and 23.7 g/min), gas temperature (475℃, 500℃, and 525℃), and the nozzle to substrate stand-off distance (3 mm, 5 mm, and 10 mm). It was found that the feed rate was the most significant parameter that affected the coating thickness. The surface porosity was most significantly affected by stand-off distance. The coating hardness was most influenced by the interaction between the feed rate and stand-off distance. An optimization study was then performed to maximize the coating thickness and hardness while minimizing the surface porosity. The optimal spray parameters (OSP) were found to be at a feed rate of 23.7 g/min, 500℃ for the carrier gas temperature, and 10 mm for the stand-off distance. The OSP yielded a coating that was 1.22 ± 0.06 mm thick, with a hardness of 364.5 ± 8.5 HV and porosity of 6.8 ± 0.6%. With a multi-parameter process, the system response is affected by both the variation in the individual parameters and the interaction of the parameters with each other. It was also concluded that the interaction between the parameters significantly affected the coating hardness. These results suggest that variation of the selected parameters produce statistically significant effects on the coating quality of WC-17Ni coatings using a low-pressure cold spray system.

Application of Simplified Parametric Model to Estimate Fan Blade-Out Response

2018 ◽  
Author(s):  
Theodore S. Brockett ◽  
Jerzy T. Sawicki
Keyword(s):  
Degrees Of Freedom ◽  
Initial Conditions ◽  
Engine Performance ◽  
Low Pressure ◽  
External Loading ◽  
System Response ◽  
Angular Rotation ◽  
Mass Eccentricity ◽  
Fan Blade ◽  
The Impact

A six-degree-of-freedom non-linear model is developed using Lagrange’s equation. The model is used to estimate transient fan-stage dynamic response during a fan-blade-out event in a turbo fan engine. The coupled degrees of freedom in the model include the fan whirl in the fan plane, the torsional response of the fan and low-pressure turbines (LPTs) about the engine centerline, the radial position of the released blade fragment, and the angular rotation of the trailing blade from its free state due to acceleration of the released blade. The released blade is assumed to slide radially outward along the trailing blade without friction. The external loading applied to the system includes fan imbalance, the remaining fan blades machining away the rub strip, rubbing of the blades with the fan case, and slowly-varying torques on the low pressure (LP) spool as engine performance degrades. The machining of the abradable imparts tangential loading on the fan blades as momentum is transferred to the liberated rub strip material. After application of the initial conditions including angular positions, angular velocities, released blade fragment position, and torsional wind-up, the governing equations are integrated forward in time from the instant the blade fragment is released. A reasonable match to test data is shown. Parameters affecting the fan-system response are varied to study the impact on fan peak lateral whirl amplitude, peak LP shaft torque, and peak loading on the trailing blade. It is found that the rub strip and mass eccentricity have the strongest influence on the LP shaft torsional loading. It is found that mass eccentricity has the largest influence on peak fan whirl. It is also found that released blade mass and attachment stiffness have the largest influence on the trailing blade loading.

The Influence of Spray Parameters on the Characteristics of Hydroxyapatite In-Flight Particles, Splats and Coatings by Micro-plasma Spraying

2018 ◽  
Vol 27 (4) ◽  
pp. 667-679 ◽  
Author(s):  
Xiao-mei Liu ◽  
Ding-yong He ◽  
Yi-ming Wang ◽  
Zheng Zhou ◽  
Guo-hong Wang ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Influence Of Spray Parameters ◽  
Spray Parameters

A spherical surface coating thickness model for a robotized thermal spray system

2019 ◽  
Vol 59 ◽  
pp. 297-304 ◽  
Author(s):  
Yanjun Zhang ◽  
Wenbo Li ◽  
Chao Zhang ◽  
Hanlin Liao ◽  
Yicha Zhang ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Coating Thickness ◽  
Surface Coating ◽  
Spherical Surface ◽  
Spray System

Characterization of Fluid Film Produced by an Atomization–Based Cutting Fluid (ACF) Spray System During Machining

2013 ◽  
Author(s):  
Alexander C. Hoyne ◽  
Chandra Nath ◽  
Shiv G. Kapoor
Keyword(s):  
Flow Characteristics ◽  
Fluid Film ◽  
Cutting Fluid ◽  
Spray Parameters ◽  
Film Model ◽  
Thin Fluid ◽  
Spray System ◽  
Thin Fluid Film ◽  
Film Development ◽  
Cooling And Lubrication

The atomization–based cutting fluid (ACF) spray system has recently been proposed as a cooling and lubrication solution for machining hard to machine materials (e.g. titanium alloys). On the tool rake face, the ACF spray system forms a thin film from cutting fluid that penetrates into the tool–chip interface to improve tool life. The objective of this work is to characterize this thin fluid film in terms of thickness and velocity for sets of ACF spray parameters. ACF spray experiments are performed by varying impingement angle in order to observe the nature of the spreading film, and to determine the film thickness at different locations after impingement of the droplets. It is observed that the film spreads radially outward producing three fluid film development zones (i.e. impingement, steady, unsteady). The steady zone is found to be between 3 and 7 mm from the focus (impingement point) of the ACF spray for the set of parameters investigated. An analytical 3D thin fluid film model for the ACF spray system has also been developed based on the equations for continuity of mass and momentum. The model requires a unique treatment of the cross–film velocity profile, droplet impingement and pressure distributions, as well as a strong gas–liquid shear interaction. The thickness profiles predicted by the analytical film model have been validated. Moreover, the model predictions of film velocity and chip flow characteristics during a titanium turning experiment reveal that the fluid film can easily penetrate into the entire tool–chip interface with the use of the ACF spray system.

528 Coating Properties Sprayed by Low Pressure Type Cold Spray System Using Hard Powders

2013 ◽  
Vol 2013.21 (0) ◽  
pp. _528-1_-_528-3_
Author(s):  
Keita KUDO ◽  
Takayuki KUWASHIMA ◽  
Yasuhiro YOSHINO ◽  
Tetsuya SONODA ◽  
Takashi SAITOH
Keyword(s):  
Cold Spray ◽  
Low Pressure ◽  
Coating Properties ◽  
Spray System

Optimization Design and Thermal Economy Analysis of the Flue Gas Treatment System in Power Plant

2015 ◽  
Author(s):  
Chunli Tang ◽  
Jianbo Li ◽  
Qingwen Qi ◽  
Chang’an Wang ◽  
Defu Che
Keyword(s):  
Flue Gas ◽  
Optimization Design ◽  
Waste Heat ◽  
Low Pressure ◽  
High Energy ◽  
Treatment System ◽  
Feed Water ◽  
Gas Temperature ◽  
Gas Treatment ◽  
Flue Gas Treatment

A novel flue gas treatment system was proposed in this paper. The system integrates the low pressure economizer (LPE) with the desulphurized flue gas heater (DFGH) for both waste heat recovery of the exhaust gas and the desulphurized flue gas heating. A model for the system was established based on the equivalent enthalpy drop theory. The thermal economic comparisons among 5 feasible connection schemes for the flue gas treatment system of a 300 MW unit were executed. The parametric analyses were also performed to evaluate the effects of the outlet flue gas temperature and the condensate temperature of the DFGH. Results indicate that the optimized flue gas treatment system can improve the thermal economy and heat the desulphurized flue gas. Better thermal economy is achieved when the LPE is connected with the high energy level feed water heater, and the low pressure extraction steam is extracted for heating desulphurized flue gas. The thermal economy decreases with the increase of the outlet flue gas temperature of the DFGH while it increases slightly with the decrease of the condensate temperature of the DFGH.

Dynamic Modeling of Vapor Compression Cycles Using a Novel Lagrangian Approach

2012 ◽  
Author(s):  
Eric S. Miller ◽  
Soumya S. Patnaik ◽  
Milind A. Jog
Keyword(s):  
Dynamic Behavior ◽  
Low Pressure ◽  
Normal Operation ◽  
System Response ◽  
Inlet Temperature ◽  
Vapor Compression ◽  
Modeling Framework ◽  
Two Phase ◽  
External Fluid ◽  
Transient System

Vapor compression cycles-based systems (VCS) are being adapted for thermal management of modern aircraft. Predicting dynamic behavior is critical to the design and control of these systems, which are likely to experience large dynamic changes in heat load. To meet this demand, a novel Lagrangian method to model the dynamic behavior of vapor compression cycles has been developed. The approach described in this paper considers the basic VCS as 4 fluid sides: one high pressure and one low pressure refrigerant side and external fluids which interact with each respectively. Sides are further divided into some number of material volumes. The model simulates compressible, unsteady flow by allowing each volume to translate and displace other elements, expanding and contracting in response to changes in mass, enthalpy and pressure. At every timestep, heat transfer to each mass element is determined and corresponding changes in thermodynamic properties are evaluated. The model predicts transient system response during normal operation as well as startup mode. Results from a dynamic evaporator simulation are presented and discussed. These results show the low-pressure refrigerant and external fluid response to changes in valve position, external fluid inlet temperature, and refrigerant inlet enthalpy. The conclusion drawn from these results is that the modeling framework described in this paper can reproduce the basic dynamics of a two-phase heat exchanger at a rate less than real time.

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