Research on Dynamic Erosion Wear Behavior of HVOF Sprayed Nanostructured WC-12Co Coating

2013 ◽  
Vol 634-638 ◽  
pp. 2997-3001
Author(s):  
Yan Liu ◽  
Hui Chen ◽  
Guo Qing Gou ◽  
Ming Jing Tu

Erosion wear is an important failure mode existing in hydropowder, petroleum, chemical industry and other fields. Nanostructured WC-Co materials possess excellent erosion wear resistance due to their outstanding combination of high hardness and excellent fracture toughness. Nanostructured WC-12Co coating was prepared by means of High Velocity Oxygen Fuel (HVOF) spraying technology in this research. The simulating experiment system was developed to study the erosion wear properties. The corundum sand with main composition of Al2O3 was used to investigate the dynamic erosion properties of nanostructured WC-12Co coating. The dynamic failure mechanism of the coatings was also analyzed by Scanning Electron Microscope (SEM). The results show that the coating is worn layer by layer in the erosion test. The bonding between the layers and the thickness of the coating should be increased to elongate the coating life.

2011 ◽  
Vol 396-398 ◽  
pp. 472-477
Author(s):  
Yan Liu ◽  
Li Jun Wang ◽  
Hui Chen ◽  
Ming Jing Tu

Nanostructured WC-12Co coating was prepared by means of High Velocity Oxygen Fuel (HVOF) spraying technology in this research. The erosion wear experiment system was developed to simulate the working condition to study the erosion wear properties. The corundum sand with main composition of Al2O3 and quartz sand with main composition of SiO2 were used to investigate the effects of sand variety on the erosion wear properties. The erosion wear failure mechanism of the coatings was also analyzed. The results show that the failure mechanism of the coating eroded by corundum sand is cracking between WC grains, while for the coating eroded by quartz sand, the failure mechanism is microcutting and microploughing.


Author(s):  
M. Kameswara Reddy ◽  
V. Suresh Babu ◽  
K. V. Sai Srinadh

The present work studies the tribological performance of Tungsten Carbide (WC) nanoparticles reinforced epoxy polymer nanocomposites. Polymer nanocomposites are prepared by hand lay-up method. Erosive wear and hardness tests were conducted to examine the physical and wear properties of epoxy/WC nanocomposites. Addition of WC nanoparticles led to significant reduction in erosion rate. In addition to that, incorporation of WC nanoparticles enhanced the hardness of epoxy nano composites. At 2% weight of WC nano filler, nanocomposites showed better performance in erosion wear properties and also in hardness. While at 3wt% of WC filler, least performance in hardness was caused by the weak adhesive bonding between the matrix and filler. The nature of erosion wear behavior was observed. Finally worn surfaces of nanocomposites were inspected using a “scanning electron microscope (SEM)”.


Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1224
Author(s):  
Zheng Wei ◽  
Yuping Wu ◽  
Sheng Hong ◽  
Weihua Yang ◽  
Wei Shi

In this study, the CoCrAlYTa-10%Al2O3 coatings were prepared by the high-velocity oxygen-fuel (HVOF) spraying. A series of ball-on-disk sliding wear tests were conducted to evaluate the tribological properties of the coatings at different temperatures (25 °C, 200 °C, 400 °C, and 600 °C). The results showed that the average coefficients of friction (COFs) of the CoCrAlYTa-10%Al2O3 coatings were lower than that of H13 steel at different temperatures. The average COFs of the CoCrAlYTa-10%Al2O3 coatings and H13 steel both decreased with increasing temperature. The wear rate of the CoCrAlYTa-10%Al2O3 coatings increased first and then decreased. The microhardness of worn surface of the CoCrAlYTa-10%Al2O3 coatings increased with increasing temperature, while the microhardness of worn surface of H13 steel at 25 °C and 200°C was higher than that at 400 °C and 600 °C. The wear mechanism of the two materials was mainly abrasive wear. The tribofilms were formed on the worn surface of the CoCrAlYTa-10%Al2O3 coatings, which had a good protective effect. Due to thermal softening and low binding strength of debris, it was difficult for H13 steel to form the tribofilms. The wear rate of H13 steel was much higher than that of the CoCrAlYTa-10%Al2O3 coatings at 400 °C and 600 °C, indicating that the high temperature wear resistance of the coatings was much better than that of H13 steel.


Author(s):  
Akash Saxena ◽  
Neera Singh ◽  
Bhupendra Singh ◽  
Devendra Kumar ◽  
Kishor Kumar Sadasivuni ◽  
...  

In the present work, phase, microstructure, and wear properties of Al2O3-reinforced Fe–Si alloy-based metal matrix nanocomposites have been studied. Composites using 2 wt.% and 5 wt.% of Si and rest Fe powder mix were synthesized via powder metallurgy and sintered at different temperature schedules. Iron–silicon alloy specimens were found to have high hardness and high wear resistance in comparison to pure iron specimens. Addition of 5 wt.% and 10 wt.% alumina reinforcement in Fe–Si alloy composition helped in developing iron aluminate (FeAl2O4) phase in composites which further improved the mechanical properties i.e. high hardness and wear resistance. Formation of iron aluminate phase occurs due to reactive sintering between Fe and Al2O3 particles. It is expected that the improved behavior of prepared nanocomposites as compared to conventional metals will be helpful in finding their use for wide industrial applications.


2017 ◽  
Vol 69 (2) ◽  
pp. 325-332 ◽  
Author(s):  
Shiyu Cui ◽  
Qiang Miao ◽  
Wenping Liang ◽  
Yi Xu ◽  
Baiqiang Li

Purpose The purpose of this study is to prepare WC-10Co-4Cr coatings using two processes of plasma spraying and high-velocity oxygen fuel (HVOF) spraying. The decarburization behaviors of the different processes are analyzed individually. The microstructural characteristics of the as-sprayed coatings are presented and the wear mechanisms of the different WC–10Co–4Cr coatings are discussed in detail. Design/methodology/approach The WC–10Co–4Cr coatings were formed on the surface of Q235 steel by plasma and HVOF spraying. Findings Plasma spraying causes more decarburizing decomposition of the WC phase than HVOF spraying. In the plasma spraying process, η(Cr25Co25W8C2) phase appears and the C content decreases from the top surface of the coating to the substrate. Practical implications In this study, two WC–10Co–4Cr coatings on Q235 steel prepared by plasma and HVOF spraying were compared with respect to the sliding wear behavior. Originality/value The wear mechanisms of the plasma- and HVOF-sprayed coatings were abrasive and oxidation, respectively.


2019 ◽  
Vol 91 (3) ◽  
Author(s):  
Marzanna Książek ◽  
Łukasz Boron ◽  
Adam Tchorz ◽  
Ryszard Grzelka

An investigation was conducted to determine the role of Co particles in the WC-Co coating produced with the High Velocity Oxygen-Fuel (HVOF) spraying on microstructure, mechanical and wear properties in a system of type: WC-Co coating/ductlile cast iron. The microstructure of the thermal sprayed WC-Co+Co coating was characterized by scanning electron (SEM) and transmission electron (TEM) microscopes as well as the analysis of chemical and phase composition in microareas (EDS, XRD). For analysis of the quality and adhesion of coatings, the scratch–test was applied. It was found that as a result of the HVOF spray of WC-Co powders with the addition of Co particles, the coatings of low porosity, high hardness, a very good adhesion to the substrate, compact structure with partially molten Co particles and finely fragmented WC particles embedded in a cobalt matrix, coming to the size of nanocrystalline sizes were obtained. Moreover, the results were discussed in reference to examination of bending strength considering cracking and delamination in the system of (WC-Co+Co)/ductile cast iron as well as hardness and wear resistance of the coating. It was found that the addition of Co particles was significantly increase resistance to cracking and wear behaviour in the studied system.


2005 ◽  
Vol 39 (2) ◽  
pp. 53-64 ◽  
Author(s):  
T.S. Sidhu ◽  
S. Prakash ◽  
R.D. Agrawal

Corrosion, erosion and abrasion, or combinations of these mechanisms, are the main cause of degradation of materials used in marine, aircraft, waste incinerators, power generation, chemical, and paper and pulp industries. One possible way to address these problems is by applying a thin layer of wear and corrosion resistant coatings. Due to the continuously rising cost of materials as well as increased material requirements, coating techniques have been given more importance in recent times. Among the different coatings techniques, high velocity oxy-fuel (HVOF) spraying process is a new and rapidly developing technology, which can yield high density coatings with porosity less than 1%, having high hardness and adhesion values, and good erosion, corrosion and wear resistance properties. The very high kinetic energy of the powder particles in the HVOF process results in the deposition of high quality coatings. It is possible to obtain a coating thickness of more than 1.5 mm with careful control of cooling to reduce residual stresses. The purpose of this paper is to review the physical, mechanical, erosion-corrosion and wear properties of the HVOF coatings and effects of deposition parameters of the process on the properties of the coatings.


2019 ◽  
Vol 36 (1−2) ◽  
Author(s):  
Ville Matikainen ◽  
S Rubio Peregrina ◽  
N Ojala ◽  
H Koivuluoto ◽  
J Schubert ◽  
...  

Thermally sprayed hardmetal coatings were produced to provide improved erosion wear compared to conventional cast GX4CrNi13-4 martensitic steel (CA6NM) used in hydro turbine components. Sprayed coatings and reference materials were tested with high-speed slurry pot tester using either fine or coarse quartz as the erosive media. Additional erosion tests were carried out with centrifugal dry erosion tester. Tungsten carbide based coatings provided the highest wear resistance due to the high hardness and even distribution of the fine carbide particles. The cast 13-4 steel samples experienced up to 180 times higher wear rates in fine quartz slurry and up to 36 times higher wear rates in coarse slurry compared to the sprayed coatings.


Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 933 ◽  
Author(s):  
Juan González ◽  
Luis Borja Peral ◽  
Alfredo Zafra ◽  
Inés Fernández-Pariente

High alloy white cast irons (WCI) play an important role in many industrial fields such as mining, cement industry, or grinding due to their high hardness and wear resistance. In all these processes, white cast iron components must work under erosion and abrasion conditions. Many investigations have been carried out with the aim of improving the mechanical properties of this type of alloys. Wear resistance depends on the mechanical properties, mainly hardness. Thus, the WCI are typically heat treated in order to modify its microstructure, improving its tribological and wear behavior. The aim of this study is to propose a mechanical surface treatment, shot peening, as an alternative to global heat treatments, due to its capacity to induce phase transformation and microstructural modification, at the same time that it improves the mechanical properties of materials. Characterization of different treated samples was performed by means of microstructural characterization, X-ray diffraction analysis, SEM observation, hardness and roughness measurements, and erosion tests. The results show that shot peening treatment is able to transform residual austenite and increase hardness in the top surface layer of the material. Both effects contribute to improve the erosion wear behavior of the WCI.


2014 ◽  
Vol 216 ◽  
pp. 261-266 ◽  
Author(s):  
Iosif Hulka ◽  
Ion Dragoş Uţu ◽  
Viorel Aurel Şerban ◽  
Petri Vuoristo ◽  
Kari Niemi ◽  
...  

The current study is focused on deposition of different carbide based powders as WC/10Co/4Cr, Cr3C2/25NiCr, CrC/37WC/18M using High Velocity Oxygen Fuel (HVOF) spraying technique onto the surface of low carbon steel substrates. The obtained coatings were characterized by means of X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to study their phases and morphology. Hardness and porosity values of the coatings were also measured. The sliding wear behavior was evaluated using the pin-on-disk method and the corrosion resistance was determined by open cell potential measurements and salt spray tests. Comparative results of the investigated samples showed that the WC/10Co/4Cr coating had the best wear properties and the Cr3C2/25NiCr coating had the best corrosion resistance.


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