EFFECT OF OXYACETYLENE FLAME REMELTING ON WEAR BEHAVIOUR OF SUPERSONIC AIR-PLASMA SPRAYED NiCrBSi/h-BN COMPOSITE COATINGS

2016 ◽  
Vol 24 (06) ◽  
pp. 1750083 ◽  
Author(s):  
N. N. ZHANG ◽  
D. Y. LIN ◽  
B. HE ◽  
G. W. ZHANG ◽  
Y. ZHANG ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coatings ◽  
Alloy Coating ◽  
Wear Behaviour ◽  
Air Plasma ◽  
X Ray ◽  
Wear And Corrosion ◽  
Before And After ◽  
Higher Temperature ◽  
Plasma Sprayed

NiCrBSi alloy coatings are widely used in wear and corrosion protection at higher temperature. As a primary hard phase forming element, B element can effectively improve the coating hardness. In this study, the low coefficient of friction of BN with three ratios (10%, 20%, and 30%) was added in order to reduce the wear rate and provide additional B element. The NiCrBSi/h-BN composite coatings were successfully prepared on a cast-iron substrate using supersonic air-plasma spray technology. The phase constitution, microstructure characterization, and microhardness of the coatings before and after oxyacetylene flame remelting were investigated by means of scanning electron microscope (SEM), X-ray diffraction, and energy dispersive analysis of X-ray techniques, respectively. The wear resistance of composite coatings was also tested in this paper. It was found that the microstructure was well refined by remelting treatment and this was beneficial for the adherence between the coating and the substrate, which was nearly 33[Formula: see text]MPa. The wear resistance of the NiCrBSi alloy coating was also improved with the increasing component of h-BN in remelted samples. When the h-BN content reached 30%, the friction coefficient decreased to 0.38 for the remelted coating. The effect of the remelting process on the anti-abrasive property and extension of the material’s wear life was quite important.

scholarly journals Composition versus Wear Behaviour of Air Plasma Sprayed NiCr–TiB2–ZrB2 Composite Coating

Coatings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 273
Author(s):  
Ning Zhang ◽  
Nannan Zhang ◽  
Sheng Guan ◽  
Shumei Li ◽  
Guangwei Zhang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
High Hardness ◽  
High Energy ◽  
Wear Behaviour ◽  
Air Plasma ◽  
X Ray Diffraction ◽  
X Ray ◽  
Energy Ball ◽  
Plasma Sprayed

The NiCr–TiB2–ZrB2 composite coating was deposited on the surface of blades made of steel (SUS304) using high-energy ball milling technology and air plasma spraying technology, which aimed to relieve the wear of the blades during operation. The influence of titanium diboride (TiB2) and zirconium diboride (ZrB2) on the microstructure and wear resistance of the coatings was investigated by X-ray diffraction, scanning electron microscopy, Vickers microhardness tester, and a wear tester. The results showed that the TiB2 and ZrB2 particles were unevenly distributed in the coatings and significantly increased the hardness and anti-wear, which contributed to their ultra-high hardness and extremely strong ability to resist deformation. The performance of the coatings was improved with the increase of the number of ceramic phases, while the hardness and wear resistance of the coating could reach their highest value when the TiB2 and ZrB2 respectively took up 15 wt.% of the total mass of the powder.

MICROSTRUCTURE OF PLASMA-SPRAYED Al2O3–ZrO2 COMPOSITE COATINGS

2006 ◽  
Vol 13 (05) ◽  
pp. 545-549 ◽  
Author(s):  
LUBIN CHEN ◽  
CHUANZHONG CHEN ◽  
LIANG ZHANG ◽  
BIAO QI ◽  
TING-QUAN LEI
Keyword(s):  
Composite Coatings ◽  
Spray Coating ◽  
Air Plasma ◽  
Air Plasma Spraying ◽  
X Ray Diffraction ◽  
Layer System ◽  
X Ray ◽  
Bond State ◽  
Bond Layer ◽  
Plasma Sprayed

Thermal barrier coatings of Al 2 O 3– ZrO 2 were prepared by air plasma spraying on the surface of 20G steel. Phase constitution, microstructures and elemental distributions of the coatings were studied by X-ray diffraction, scanning electron microscope and electron probe X-ray microanalysis. The results show that the plasma spray coating mainly consists of α- Al 2 O 3, c - ZrO 2, and t - ZrO 2. The bond state of the interface between the top layer and bond layer is fine, and the bond layer has a good combination with the substrate. ZrO 2 and Al 2 O 3 structures can closely integrate together and form compact top layer system.

scholarly journals Electrodeposition of Transition Metal Composites on Mild Steel: Structural and Wear Behaviour

2019 ◽  
Vol 8 (6S) ◽  
pp. 534-539
Keyword(s):  
Wear Resistance ◽  
Transition Metal ◽  
Mild Steel ◽  
Composite Coatings ◽  
Wear Behaviour ◽  
Metal Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pin On Disc ◽  
Structural Characterizations

Wear characteristics of the transition metal composite (TMC) coated mild steel are investigated. TMC coatings were performed using electrodeposition technique on mild steel. Different concentrations of transition metals were subjected to prepare the TMC’s and studied. The structural and the micro structural studies of the composites coatings were studied through X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The elemental compositions of coated composites were evaluated using Energy dispersive X-ray diffraction (EDS) studies. Both the structural and micro structural characterizations confirmed the formation of composite coatings. Further, it is evident from the EDS analyses that TMC’s are coated with the desired concentrations. In order to understand the wear resistance of coated mild steel, the specimen were subjected to load on pin-on-disc type wear tester. The effects of concentration of composite and thickness of the coating on wear resistance are discussed. The coating results in improving the wear resistance and hardness of the specimen

scholarly journals Effect of Carbon Fiber Addition on the Microstructure and Wear Resistance of Laser Cladding Composite Coatings

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 684 ◽  
Author(s):  
Jianfeng Li ◽  
Zhencai Zhu ◽  
Yuxing Peng ◽  
Gang Shen
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Carbon Fibers ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Alloy Coating ◽  
X Ray ◽  
Nano Size ◽  
Original Coating

In this study, the effect of carbon fibers (CFs) on the microstructure and wear resistance of Fe-based alloy coating produced by laser cladding was investigated by X-ray diffractometer (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometer (EDS), and wear tester. The results indicated that with the addition of CFs, the microstructure of the composite coating mainly transformed from α-Fe cellular dendrites and γ-Fe/(Cr, Fe)7C3/CrB eutectics to bulk-like (Cr, Fe)7C3, nano-size B4C, and γ-(Fe, Ni)/(Cr, Fe)23C6 lamellar eutectics. Additionally, the microhardness and wear resistance of the composite coating compared with the original coating both increased by approximately two times. The original coating showed the dominant wear mechanisms of micro-cutting and serious brittle spalling, while the composite coating with CFs showed the main wear mechanism of slight scratching.

Microstructure and Properties of WC-CO-Cr Coatings

1996 ◽  
Author(s):  
L.-M. Berger ◽  
P. Vuoristo ◽  
T. Mäntylä ◽  
W. Kunert ◽  
W. Lengauer ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Practical Importance ◽  
Wear Test ◽  
Wear Behaviour ◽  
Metallic Binder ◽  
Microstructure And Properties ◽  
Wear And Corrosion ◽  
Number Of Publications ◽  
Wear And Corrosion Resistance

Abstract WC-Co-Cr represents an important composition for hardmetal-like coatings which is appHed when simuhaneous wear and corrosion resistance is required. In this paper five commercially available spray powders obtained by various production techniques (sintered and crushed as well as agglomerated and plasma-densified) of the composition WC-10%Co- 4%Cr have been thoroughly characterized and were sprayed by DCS, HVOF (CDS process) and APS. The microstructures of the coatings were characterized and their wear behaviour was investigated by means of an abrasion wear test. For the best of these powders the wear resistance was nearly equal for the DGS and HVOF coatings. Other powders show significant differences with respect to their processabilities in these spray processes. APS coatings from all powders, obtained with an Ar/H2 plasma showed inferior microstructures and significant lower wear resistance. The spray powder compositions, grain sizes and structures were found to determine the processability of the powders and the microstructure and properties of the coatings. COMPOSITE MATERIALS of the type hard phase - metallic binder with WC and CoCr as constituents are widely used for the preparation of hardmetal-like coatings. The chromium addition to the metallic binder is thought to improve its corrosion resistance in comparison with pure WC-Co. This has led to many applications of WC-CoCr coatings where simultaneous wear and corrosion resistance is required. Despite of its significant practical importance only a limited number of publications is devoted to detailed questions of structure and properties of WC-CoCr coatings (1-3). In some comparative studies such coatings have been investigated together with WC-Co and Cr3C2-NiCr coatings (4-8). However, systematic investigations of spray powder compositions and morphologies as well as investigations of the influence of different thermal spray processes on coating structures and properties which have repeatedly been provided for WC-Co (for example (9, 10)) are missing for WC-CoCr. In this paper a short survey of literature on the phase relationships in the WC-CoCr system and the effect of chromium additions on the properties of sintered parts and thermally sprayed coatings compared to WC-Co is given. In the experimental part a systematic study of the influence of the preparation process on composition and morphology of commercially available WC-10%Co-4%Cr spray powders was provided. These powders have been sprayed by DGS, HVOF and APS and the microstructure and basic properties of the coatings have been studied.

scholarly journals Arc Thermal Spray NiCr20 Alloy Coating: Fabrication, Sealant, Heat Treatment, Wear, and Corrosion Resistances

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Van Tuan Nguyen ◽  
Quy Le Thu ◽  
Tuan Anh Nguyen ◽  
Quoc Cuong Ly ◽  
Ly Pham Thi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Wear Resistance ◽  
Corrosion Resistance ◽  
Phase Composition ◽  
Corrosion Test ◽  
Annealing Temperature ◽  
Alloy Coating ◽  
Aluminum Phosphate ◽  
Annealing Temperatures ◽  
Wear And Corrosion

This study presents the effect of heat treatment on porosity, phase composition, microhardness, and wear and corrosion resistances of the thermal sprayed NiCr20 coating after sealing with aluminum phosphate. The annealing temperatures were varied in a range of 400 to 1000°C. The obtained results indicated the porosity of coating decreased with increasing the annealing temperature. After treatment at temperatures in range of 800-1000°C, more than 90% of initial pores in the coating were successfully filled with the sealants. The XRD data revealed not only the formation of new phases of other compounds, but also the interaction between coating and sealant. After heat treatment, wear resistance of coating was 12 times higher than that without heat treatment. The corrosion test in H2SO4 solution indicated that the presence of sealant in coatings increased their corrosion resistance. From these findings, application of these NiCr20 coatings to protect steel against wear and corrosion appears very promising.

MICROSTRUCTURE AND WEAR RESISTANCE OF IN-SITU SYNTHESIZED TiB2–TiC/Fe COMPOSITE COATING BY LASER CLADDING

2020 ◽  
pp. 2050046
Author(s):  
TIANWEI YANG ◽  
ZHAOHUI WANG ◽  
SHIHAI TAN ◽  
FU GUO
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Material Surfaces ◽  
Metallurgical Bonding ◽  
Steel Surfaces

To increase the strength and wear resistance of material surfaces, various combinations of B4C and 80TiFe powder were mixed into a Fe60 self-fluxing alloy powder; the composite coatings reinforced by TiB2–TiC were successfully prepared on Q235 steel surfaces by laser cladding. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were used to study the microstructure and chemical and phase composition. Microhardness and wear testers were used to investigate the mechanical properties. The results show that the interfaces of composite coatings and substrate materials are excellent for metallurgical bonding. The block-like TiB2 particles and flower-like TiC particles are uniformly distributed in the cladding coating. When the mass fraction of the mixed powder is 30%, the average microhardness of the coating is approximately 1100 HV[Formula: see text], which is 50% higher than that without the mixed powder, and demonstrates the best wear with a performance twice as better as that of the substrate.

Wear behaviour of plasma-sprayed AlSi/B4C composite coatings

2007 ◽  
Vol 28 (7) ◽  
pp. 2177-2183 ◽  
Author(s):  
Ozkan Sarikaya ◽  
Selahaddin Anik ◽  
Erdal Celik ◽  
S. Cem Okumus ◽  
Salim Aslanlar
Keyword(s):  
Composite Coatings ◽  
Wear Behaviour ◽  
Plasma Sprayed

scholarly journals Composite Coatings of Chromium and Nanodiamond Particles on Steel

2017 ◽  
Vol 62 (4) ◽  
pp. 2421-2424 ◽  
Author(s):  
N. Gidikova ◽  
M. Sulowski ◽  
V. Petkov ◽  
R. Valov ◽  
G. Cempura
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Composite Coating ◽  
Composite Coatings ◽  
Machine Building ◽  
Chromium Coating ◽  
Detonation Synthesis ◽  
Micro Structure ◽  
X Ray ◽  
Average Size

AbstractChrome plating is used to improve the properties of metal surfaces like hardness, corrosion resistance and wear resistance in machine building. To further improve these properties, an electrodeposited chromium coating on steel, modified with nanodiamond particles is proposed. The nanodiamond particles (average size 4 nm measured by TEM) are produced by detonation synthesis (NDDS). The composite coating (Cr+NDDS) has an increased thickness, about two times greater microhardness and finer micro-structure compared to that of unmodified chromium coating obtained under the same galvanization conditions. In the microstructure of specimen obtained from chrome electrolyte with concentration of NDDS 25 g/l or more, “minisections” with chromium shell were found. They were identified by metallographic microscope and X-ray analyser on etched section of chromium plated sample. The object of further research is the dependence of the presence of NDDS in the composite coating from the nanodiamond particles concentration in the chroming electrolyte.

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