Two-Body Dry Abrasive Wear Performance of High Velocity Oxygen Fuel Spray Process and Electrodeposited Cermet Coatings

2017 ◽  
Vol 888 ◽  
pp. 131-135 ◽  
Author(s):  
Nur Amira Mohd Rabani ◽  
Zakiah Kamdi

In order to protect parts against wear, the carbon steel used are commonly coated by cermet coatings to increase the wear resistance. In this paper, the coatings consist of tungsten carbide 17wt% cobalt (WC-17Co), tungsten carbide 9wt% nickel (WC-9Ni), electrodeposited nickel (electro Ni) and electrodeposited nickel-silicon carbide (electro Ni-SiC) coatings. All coatings are deposited onto AISI 1018 carbon steel by using two different methods which are high velocity oxygen fuel (HVOF) and co-electrodeposition method. Abrasive wear test were observed under two‑body dry abrasion conditions with pin-on-disc test arrangement. Based on the volume loss after the wear test, the wear rates were calculated by using Archard’s law. The wear tracks of the coatings were investigated by using scanning electron microscope (SEM) and atomic force microscopy (AFM). The hardness of each coating was measured by using Vickers microhardness. The results showed that HVOF coatings have lower wear rate compared to the electrodeposited coatings. WC-9Ni has the lowest wear rate which is 4.06×10-3 mm3/Nm much lower compared to electro Ni-SiC of 16.36×10-3 mm3/Nm. This result was expected as the hardness of WC-9Ni is 1625.37 HV higher than electrodeposited coatings which approximately 380.51 HV. In conclusion, the methods of coating deposited affect the wear resistance as well as the hardness of the coatings.

Author(s):  
Zhetcho Doinov Kalitchin ◽  
Mara Krumova Kandeva ◽  
Yana Petrova Stoyanova

This research work studies the characteristics of wear and wear resistance of composite powder coatings, deposited by high-velocity oxygen fuel, which contain composite mixtures Ni-Cr-B-Si having different chromium concentrations – 9.9%; 13.2%; 14%; 16% and 20% , at one and the same size of the particles and the same content of the remaining elements. The coating of 20% Cr does not contain B and Si. Out of each powder, composite coatings have been prepared without any preliminary thermal treatment of the substrate and with preliminary thermal treatment of the substrate up to 650оС. The coatings have been tested under identical conditions of dry friction over a surface of solid firmly attached abrasive particles using the tribological testing device „Pin-on-disk“. Results have been obtained and the dependences of the hardness, mass wear, intensity of the wearing process, absolute and relative wear resistance on the Cr concentration under identical conditions of friction. It has been found out that for all the coatings the preliminary thermal treatment of the substrate leads to a decrease in the wear intensity. Upon increasing Cr concentration the wear intensity diminishes and it reaches minimal values at 16% Cr. In the case of coatings having 20% Cr concentration, the wear intensity is increased, which is due to the absence of the components B and Si in the composite mixture, whereupon no inter-metallic structures are formed having high hardness and wear resistance. The obtained results have no analogues in the current literature and they have not been published by the authors.


2018 ◽  
Vol 929 ◽  
pp. 142-149 ◽  
Author(s):  
Myrna Ariati Mochtar ◽  
Wahyuaji Narottama Putra ◽  
Raditya Perdana Rachmansyah

Tube boiler operating condition initiates common problems that can occur as a problem in the wear resistance material. It leads to a decreased function of the material so that it is necessary to repair or replacement. High Velocity Oxygen Fuel (HVOF) is regarded as one of the effective methods to increase the wear resistance of the material. In this study, the materials were ASTM SA213-T91 as a material commonly used for boiler tube and JIS G 3132 SPHT-2 as an alternative material. In the early stages, both of specimens were given initial surface heating with temperature variations 0, 50, 100 and 150oC. The materials were then coated with Stellite-1 using HVOF method. The material were then characterized for the microstructure, porosity, hardness distribution, and wear resistant. The results showed that the coating Stellite-1 as a top coat with HVOF method can improve the performance of the material. Microhardness increases from 220 HV to 770 HV on ASTM SA213-T91, while on the substrate JIS G 3132 SPHT-2 the microhardness increased from 120 HV to 750 HV. Better wear resistance was achieved with increasing preheating [1]. Wear resistance of the materials increased from the range 3.69x10-7at 0°C preheating up to 0.89x10-7on a specimen with initial surface heating 150oC. Porosity also decreases with the increasing preheating temperature.


2012 ◽  
Vol 518-523 ◽  
pp. 3984-3988
Author(s):  
Bai Lin Zha ◽  
Xiao Jing Yuan ◽  
De Wen Wang

Environmental protection and worker safety measures against the extensively used hard chrome plating (EHC) is becoming more stringent, which leads to the development and application of alternative technology. As one of the most promising replacement technology of EHC, WC/Co coatings deposited by High Velocity Oxygen Fuel (HVOF) have well performances in corrosion and wear resistance. The paper analyzed technical characteristics, property and cost of EHC and HVOF deposited WC-Co coatings, while results show that performance of HVOF sprayed WC-Co coatings is superior or equal to EHC with much higher expense, so current replacement of EHC by HVOF centers airplane and military arm field which have relatively higher profit.


Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 660
Author(s):  
Qun Wang ◽  
Yingpeng Zhang ◽  
Xiang Ding ◽  
Shaoyi Wang ◽  
Chidambaram Seshadri Ramachandran

In order to investigate the effect of WC grain size on coatings’ properties and abrasive wear performance, a few WC-20Cr3C2-7Ni coatings with three different WC grain sizes were deposited by the high-velocity oxy-fuel (HVOF) thermal spray process. The phase compositions, microstructures, and mechanical properties of the coatings were investigated. Furthermore, the two- and three-body abrasive wear performances of the three coatings were tested by using SiC and SiO2 abrasives, respectively. The results show that all the three coatings were composed of WC, Cr3C2, and the Ni binder as well as the (W,Cr)2C phase. The abrasive wear resistance of the WC-20Cr3C2-7Ni coating monotonously increased with increasing WC grain size when the SiC abrasive was used in the two- and three-body abrasive wear tests. However, the wear resistance trend was reversed when the SiO2 abrasive was used in the three-body abrasive wear test. The specific wear rate of the WC-20Cr3C2-7Ni coating exposed to the SiC abrasive under the two-body abrasive wear test was the largest. The wear resistance of the coatings was more significantly affected by the hardness of the abrasive particles than the size of carbides present within the coating. The high hardness of SiC can cut both the carbide and the binder phase of the WC-based cermet coatings, resulting in a high wear rate, whereas the low hardness of SiO2 cuts and/or scratches the binder initially, and then it dislodges the carbides from the matrix. The dislodged carbides which were subsequently pulled out from the matrix by the repeated impact of the SiO2 abrasives result in a milder wear rate.


2019 ◽  
Vol 11 (5) ◽  
pp. 685-693 ◽  
Author(s):  
Zhidan Zhou ◽  
Xiubing Liang ◽  
Yongxiong Chen ◽  
Baolong Shen ◽  
Junchao Shang ◽  
...  

2020 ◽  
Vol 2 (1) ◽  
pp. 25
Author(s):  
Mirosław Szala ◽  
Mariusz Walczak ◽  
Leszek Łatka ◽  
Kamil Gancarczyk

Bulk cobalt- and nickel-based metallic materials exhibit superior resistance to cavitation erosion and sliding wear. Thus, thermally deposited High-Velocity Oxygen Fuel (HVOF) coatings seem promising for increasing the wear resistance of the bulk metal substrate. However, the effect of chemical composition on the cavitation erosion and sliding wear resistance of M(Co,Ni)CrAlY and NiCrMo coatings has not yet been exhaustively studied. In this study, High-Velocity Oxygen Fuel (HVOF) coatings such as CoNiCrAlY, NiCoCrAlY, and NiCrMoFeCo were deposited on AISI 310 (X15CrNi25-20) steel coupons. The microstructure, hardness, phase composition and surface morphology of the as-sprayed coatings were examined. Cavitation erosion tests were conducted using the vibratory method in accordance with the ASTM G32 standard. Sliding wear was examined with the use of a ball-on-disc tribometer, and friction coefficients were measured. The mechanism of wear was identified with the scanning electron microscope equipped with an energy dispersive spectroscopy (SEM-EDS) method. In comparison to the NiCrMoFeCo coating, the CoNiCrAlY and NiCoCrAlY coatings have a lower sliding and cavitation wear resistance.


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