High Velocity Wire Flame Spraying (HVWFS) of Molybdenum

2000 ◽  
Author(s):  
Fr.-W. Bach ◽  
T. Copitzky ◽  
Z. Babiak ◽  
T. Duda
Keyword(s):  
High Velocity ◽  
Flame Spraying ◽  
Wear Properties ◽  
Spray System ◽  
High Particle ◽  
Lower Porosity ◽  
Hardening Mechanisms ◽  
Particle Velocities ◽  
Wear Resistance Coatings ◽  
Sprayed Coatings

Abstract Wire flame sprayed molybdenum is a wide used procedure for manufacturing of wear resistance coatings. The properties of thermal sprayed coatings depend mainly on the kinetic and thermal energy of sprayed particles, i.e., a higher particle velocity causes an increase of coating quality. The now available high velocity spray system from Praxair which is used within this work is capable to realise the aim of high particle velocities. The coating properties presented in this work are analysed in comparison to conventional wire and powder plasma spray processes. HVWFS molybdenum coatings show lower porosity, higher adhesion and cohesion and better wear properties. To explain the results, particle size distribution, oxygen/carbon content and structure are analysed. Hardening mechanisms of coatings and their adhesion/cohesion properties are discussed based on light microscopy, SEM, XRD and TEM investigations.

Thermal Spray Processing of WC-Co Nanomaterials

2000 ◽  
Author(s):  
J. Voyer ◽  
B.R. Marple
Keyword(s):  
Phase Composition ◽  
Recent Work ◽  
Phase Analysis ◽  
Thermal Spraying ◽  
Volume Percent ◽  
Wear Properties ◽  
Lower Porosity ◽  
Hvof Thermal Spraying ◽  
Spray Processing ◽  
Sprayed Coatings

Abstract WC-Co based cermets are extensively used in wear applications due to their hardness and toughness. Recent work has demonstrated the potential for using nanoscale constituents to improve the wear properties of these materials. In the present study, two WC-Co powders containing a nanosized WC phase were used to produce coatings by HVOF thermal spraying. These powders had similar properties except for the volume percent binder present: WC-8C0 and WC-12Co. The thermal spraying conditions were varied in order to identify their effect on the microstructure, properties and phase composition of the sprayed coatings. The as-sprayed coatings possess porosity values ranging between 1% and 2% and microhardness values (HV100) from 1150 to 1550, which are quite similar to values obtained for conventionally sized WC-based coatings. For all the coatings, phase analysis indicated significant degradation of the WC phase to produce W2C, W, CO3W3C and Co6W3C. For some spray conditions, even WO3 phase was found in the coatings. The JP-5000 HVOF system produces coatings with lower porosity, similar microhardness values and, more importantly, with lower WC degradation than the coatings produced with the DJ-2700.

Wear Properties of WC/Co Coatings with Plasma and High Velocity Oxyfuel Spraying

1998 ◽  
Author(s):  
T. Akasawa ◽  
K. Ai
Keyword(s):  
High Velocity ◽  
Material Removal ◽  
Sliding Wear ◽  
Substrate Surface ◽  
Wear Properties ◽  
Hvof Spraying ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed ◽  
Steel Substrates ◽  
Sprayed Coatings

Abstract A tungsten carbide/cobalt hard coating was deposited on steel substrates using plasma-arc and high velocity oxyfuel flame (HVOF) spraying. The characteristics of the coatings made by the two spraying methods were evaluated under identical conditions. The microstructure and the chemical composition ofthe coatings were different depending on the powderheating temperature and the velocity of particles. The sliding wear properties of the coatings against hardened steel at high sliding speeds showed different tendencies from those at low speeds. The plasma sprayed coatings resulted in better abrasive wear properties than HVOF coatings did. Material removal by solid particle erosion depended on the striking angle ofparticles on the substrate surface but there are no clear differences in wear properties between the two coatings.

scholarly journals GATOR-GARD: The Process, Coatings, and Turbomachinery Applications

1986 ◽  
Author(s):  
Thomas F. Lewis
Keyword(s):  
High Temperature ◽  
Erosive Wear ◽  
Cost Effective ◽  
Effective Solution ◽  
Ionized Gas ◽  
High Particle ◽  
Particle Velocities ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings ◽  
Turbine Exhaust

The GATOR-GARD® process uses a high temperature, high velocity, ionized gas to deposit metal or ceramic particles on substrate materials. The high particle velocities and their extremely short dwell time at high temperature produces dense, well bonded coatings with unique structures which can be tailored for maximum resistance to wear, erosion and impact. The selective usage of metal and ceramic thermal sprayed coatings on turbomachinery components for repair or original equipment protection is a cost effective solution to today’s high maintenance costs. GATOR-GARD coatings are used to protect new components from sliding, fretting, and erosive wear from the compressor to the turbine exhaust fairings, at metal temperatures from ambient to more than 1040 degrees C (1900 F). When used for repair of worn components, these coatings improve the life many times over the original equipment.

High Velocity Oxy-Fuel Flame Spraying-Process and Coating Characteristics

1996 ◽  
Author(s):  
H. Kreye ◽  
R. Schwetzke ◽  
S. Zimmermann
Keyword(s):  
Thermal Energy ◽  
High Velocity ◽  
Flame Spraying ◽  
Internal Stresses ◽  
Spray Coatings ◽  
Spray Process ◽  
Carbide Coatings ◽  
Coating Characteristics ◽  
Particle Velocities ◽  
First And Second Generation

Abstract High velocity oxy-fuel (HVOF) spray experiments were carried out using various spray systems. A comparison is made of the systems introduced as a first and second generation (Jet Kote, Diamond Jet, Top Gun, CDS) with the more recently introduced systems of the third generation (JP 5000, DJ 2600, DJ 2700). The comparison is based on particle velocities and experiments to evaluate the heat transfer to the particles. The results show that the systems of the new generation with a converging-diverging nozzle section can produce up to 50% higher particle velocities. The higher kinetic energy allows to reduce the thermal energy and to reduce thermally activated phase transformations of the coating material during the spray process. Carbide coatings produced with one of the new HVOF systems exhibit a higher density, higher bond strength and higher hardness as compared to coatings produced with one of the systems of the first and second HVOF generation. Furthermore, the reduced thermal energy yields less oxidative loss of carbon and opens the possibility to spray coatings with neutral or compressive internal stresses, a prerequisite to produce carbide coatings up to a thickness of several millimeters.

Structure and Properties of Coatings Deposited by High Velocity Arc Spray Technique

1999 ◽  
Vol 122 (3) ◽  
pp. 646-649 ◽  
Author(s):  
Binshi Xu ◽  
Wei Zhang ◽  
Shining Ma ◽  
Baohong Tian ◽  
Xiubing Liang
Keyword(s):  
High Velocity ◽  
Test Results ◽  
Structure And Properties ◽  
Wear Properties ◽  
Properties Of Coatings ◽  
Spray Coatings ◽  
Arc Spray ◽  
Spray Technique ◽  
The Difference ◽  
Sprayed Coatings

The microstructure of spray coatings using a newly developed thermal spray technique, High Velocity Arc Spray (HVAS), was studied and compared with those of regular arc sprayed coatings. The mechanical and wear properties of HVAS coatings were also investigated. The test results showed that HVAS coatings had better mechanical properties than those of regular arc sprayed coatings. The bonding strength of HVAS Al and 3Cr13 coatings was increased by 114 percent and 51.8 percent; the relative wear resistance of HVAS coatings was about twice that of regular arc sprayed coatings. The difference of microstructure and tribological properties between HVAS and regular arc sprayed coatings was discussed. [S0742-4787(00)00203-4]

Sliding Wear Behavior of Remelted Al2O3-TiO2 Plasma Sprayed Coatings on Titanium

2016 ◽  
Vol 254 ◽  
pp. 231-236 ◽  
Author(s):  
Ion Dragoş Uţu ◽  
Gabriela Marginean ◽  
Iosif Hulka ◽  
Viorel Aurel Şerban
Keyword(s):  
Sliding Wear ◽  
Wear Behavior ◽  
Pure Titanium ◽  
Titanium Substrate ◽  
Atmospheric Plasma ◽  
Wear Properties ◽  
Before And After ◽  
Sprayed Coating ◽  
Pin On Disk ◽  
Sprayed Coatings

Microstructure and wear properties of the Al2O3-13.wt% TiO2 thermally sprayed coatings before and after remelting were investigated in this study. The coatings were deposited on a pure titanium substrate using the atmospheric plasma spraying (APS) process. The as-sprayed coatings were electron beam (EB) modified in order to improve their compactness and bonding strength.The effect of EB remelting on the microstructure, phase constituents and wear properties was investigated using scanning electron microscopy (SEM), X-Ray diffraction technique and hardness measurements. The sliding wear behavior was tested using a pin on disk method.The results showed that the remelting process had a positive effect removing the lamellar defect of the as-sprayed coating and improving the compactness, hardness and wear behavior.

Surface Wear Improvement of Al-Alloys by Amorphous Iron-Based Flame-Sprayed Coatings

2011 ◽  
Vol 690 ◽  
pp. 405-408 ◽  
Author(s):  
Joel Voyer
Keyword(s):  
Wear Resistance ◽  
Flame Spraying ◽  
Flame Spray ◽  
Phase Content ◽  
Coating Properties ◽  
Amorphous Iron ◽  
Spray Process ◽  
Spraying Parameters ◽  
Iron Based ◽  
Sprayed Coatings

Partially amorphous iron-based coatings were produced onto aluminium using a powder flame-spraying process with a commercially available feedstock powder (Nanosteel SHS-7170) obtained from the Nanosteel Company Inc.. Several coating properties such as the microstructure, porosity, phase content, micro-hardness, and wear resistance were evaluated in the as-sprayed condition. As shown by the results obtained, the powder flame iron-based coatings perform relatively well in term of wear resistance in comparison with similar coatings produced using other expensive thermal spray techniques. Furthermore, this study shows that all the coating properties (microstructure, porosity, phase content, hardness and wear performance) depend strongly on the flame spraying parameters used. Finally, this paper demonstrates clearly that the flame-spray process may be used to produce amorphous iron-based coatings having a good wear resistance, and that this process appears to be a suitable inexpensive alternative to plasma or HVOF processes based on the present results.

scholarly journals High velocity suspension flame spraying (HVSFS) of metal doped bioceramic coatings

2017 ◽  
Vol 2 (3) ◽  
pp. 162-169 ◽  
Author(s):  
P. Krieg ◽  
A. Killinger ◽  
R. Gadow ◽  
S. Burtscher ◽  
A. Bernstein
Keyword(s):  
High Velocity ◽  
Flame Spraying ◽  
Metal Doped ◽  
Bioceramic Coatings
Sign in / Sign up

Export Citation Format

Share Document