The Use of Hard Alloy Waste in Composite Galvanic Coatings for the Restoration of Car Parts

2020 ◽  
Vol 299 ◽  
pp. 258-263
Author(s):  
Boris A. Semenikhin ◽  
Lyubov P. Kuznetsova ◽  
Vladimir I. Kozlikin
Keyword(s):  
Particle Size ◽  
Wear Resistance ◽  
Tungsten Carbide ◽  
Hard Alloy ◽  
Dispersed Phase ◽  
Hard Alloys ◽  
Time Increase ◽  
Micro Hardness ◽  
Repair Costs ◽  
Iron Plating

The results of the research of the use of powders based on tungsten carbide with a particle size of 1 μm or less, obtained by the method of electro-erosion dispersion from the waste of sintered hard alloys, as a dispersed phase of composite galvanic coatings based on iron during the restoration and hardening of car parts are presented. It is shown that the introduction powders of hard alloys of grades VK8 and T15K6 in the chloride electrolyte of iron plating with a concentration of 100 g/l and more, practically does not affect the micro-hardness, but allows to increase the relative wear resistance of the obtained composite galvanic coatings, compared to simple iron galvanic coatings, and, at the same time, increase the life of parts and reduce repair costs.

scholarly journals Effect of Particle Size on Microstructure and Element Diffusion at the Interface of Tungsten Carbide/High Strength Steel Composites

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4164 ◽  
Author(s):  
Hongmei Zhang ◽  
Hongnan Li ◽  
Ling Yan ◽  
Chao Wang ◽  
Fangfang Ai ◽  
...  
Keyword(s):  
Particle Size ◽  
Tungsten Carbide ◽  
High Strength Steel ◽  
Average Particle Size ◽  
High Strength ◽  
Average Particle ◽  
Micro Hardness ◽  
Vacuum Sintering ◽  
Element Diffusion ◽  
Average Grain Size

The microstructure and micro-hardness of tungsten carbide/high strength steel (WC/HSS) composites with different particle sizes were analyzed by optical microscopy (OM), scanning electron microscopy (SEM), ultra-high temperature laser confocal microscopy (UTLCM) and micro-hardness testing. The composites were prepared by cold pressing and vacuum sintering. The results show that WC density tends to increase as the average grain size of WC decreases and the micro-hardness of WC increases with the decrease of WC particle size. The micro-hardness of WC near the bonding interface is higher than that in other regions. When the particle size of WC powder particles is 200 nm, a transition layer with a certain width is formed at the interface between WC and HSS, and the combination between the two materials is metallurgical. The iron element in the HSS matrix diffuses into the WC structure in contact with it, resulting in a fusion layer of a certain width, and the composite interface is relatively well bonded. When the average particle size of WC powder is 200 nm, W, Fe and Co elements significantly diffuse in the transition zone at the interface. With the increase of WC particle size, the trend of element diffusion decreases.

Influence of thermal cycling modes on VK8 hard alloy mechanical and tribological properties

2020 ◽  
pp. 55-65
Author(s):  
S. I. Bogodukhov ◽  
E. S. Kozik ◽  
E. V. Svidenko
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
Wear Resistance ◽  
Thermal Cycling ◽  
Hard Alloy ◽  
Tribological Properties ◽  
High Speed ◽  
Metal Cutting ◽  
Hard Alloys ◽  
Mechanical And Tribological Properties

Hard alloys are popular materials widely used in the toolmaking industry. Refractory carbides included in their composition make carbide tools very hard (80 to 92 HRA) and heat-resistant (800 to 1000 °С) so as they can be used at cutting speeds several times higher than those used for high-speed steels. However, hard alloys differ from the latter by lower strength (1000 to 1500 MPa) and the absence of impact strength, and this constitutes an urgent problem. We studied the influence of thermal cycling modes on the mechanical and tribological properties of VK8 (WC–8Co) hard alloy used in the manufacture of cutters and cutting inserts for metal working on metal-cutting machines. As the object of study, we selected 5×5×35 mm billets made of VK8 (WC–8Co) alloy manufactured by powder metallurgy methods at Dimitrovgrad Tool Plant. The following criteria were selected for heat treatment mode evaluation: Vickers hardness, flexural strength, and mass wear resistance (as compared to the wear of asreceived samples that were not heat treated). Plates in the initial state and after heat treatment were subjected to abrasion tests. Wear results were evaluated by the change in the mass of plates. Regularities of the influence of various time and temperature conditions of heat treatment on the tribological properties of products made of VK group tungsten hard alloys were determined. An increase in the number of thermal cycling cycles improved such mechanical properties of the VK8 hard alloy as strength and hardness. When repeating the cycles five times, an increase in abrasive wear resistance was obtained compared to the initial nonheat-treated sample. The elemental composition of the VK8 hard alloy changed insignificantly after thermal cycling, only a slight increase in oxygen was observed on the surface of plates. The grain size after thermal cycling increased in comparison with the initial VK8 hard alloy. It was found that VK8 hard alloy thermocyclic treatment leads to a change in the phase composition. X-ray phase analysis showed the presence of a large amount of α-Co with an hcp-type lattice on the surface of a hard alloy and a solid solution of WC in α-Co. A change in the cobalt modification ratio causes a decrease in microstresses. An analysis of the carbide phase structure state showed that the size of crystallites and microstresses changed after thermal cycling. The lattice constant of the cobalt cubic solid solution decreased, which may indicate a decrease in the amount of tungsten carbide and carbon dissolved in it. Statistical processing of experimental results included the calculation of the average value of the mechanical property, its dispersion and standard deviation in the selected confidence interval.

Mechanical Milling Prepared Nano-Sized Al2O3 Particles Utilized in Electroless Plating Ni-P- Al2O3 Composite Coatings

2012 ◽  
Vol 602-604 ◽  
pp. 1700-1705 ◽  
Author(s):  
Ai Zhi Yu ◽  
Mao Dong Li ◽  
Jin Mei Lin ◽  
Shu Kuan Zhang
Keyword(s):  
Heat Treatment ◽  
Particle Size ◽  
Wear Resistance ◽  
Mechanical Milling ◽  
Chemical Method ◽  
Composite Coatings ◽  
Micro Hardness ◽  
Mechanical Method ◽  
Al2o3 Composite ◽  
Steel Substrates

In this paper, nano-sized Al2O3 particles were prepared by mechanical milling, and Ni-P-Al2O3 composite coatings were plated on Q235 steel substrates, which plating solutions were containing different concentrations Al2O3 particles. The morphology, phase and particle size distribution of the as-prepared Al2O3 particles, and the properties of the coatings were investigated. The results show that, the morphology of the as-prepared Al2O3 particles were spherical and almost size under 100nm, the coatings were uniformly thickness and the Al2O3 particles were uniformly dispersed in the coatings, after heat treatment, the micro-hardness and wear resistance of the coatings were significantly improved, compared with the chemical method prepared Al2O3 particles, the mechanical method prepared Al2O3 particles had the same performance in improving the micro-hardness of the coatings.

scholarly journals Perspectives of the industrial recycling of hard-alloy materials waste by electro-erosive grinding

2018 ◽  
Vol 224 ◽  
pp. 01010
Author(s):  
Kharis Rakhimyanov ◽  
Valentina Marusina
Keyword(s):  
Mechanical Properties ◽  
Specific Surface ◽  
Tungsten Carbide ◽  
Hard Alloy ◽  
Physical And Mechanical Properties ◽  
Spherical Shape ◽  
Production Waste ◽  
Hard Alloys ◽  
Sustainable Technologies ◽  
Powder Particles

The creation of efficient industries is possible by using sustainable technologies based on the processes of recycling of the production waste. First of all, it refers to expensive material waste, including hard alloys. The electro-erosive grinding is considered to be the effective method of recycling such materials. The results of research on recycling the tungsten-cobalt hard alloy show the possibility of obtaining tungsten-carbide powders possessing improved physical and mechanical properties. The technology mentioned is also perspective for recycling tungstenless hard-alloy waste both at the laboratory devices equipped with the RC-generator and at the industrial installations of bulky grinding. It is established experimentally that the electro-erosive grinding of the TN20 tungstenless hard alloy at the laboratory provides obtaining the main volume (up to 85%) of the powder particles of the spherical shape having a dimension of 5 µm and the specific surface of 31.5 m2/g. Higher physical and mechanical properties of powders are also provided during recycling the TN20 alloy waste at the industrial installations of bulky grinding.

Wear Resistance of Ion Implanting Tungsten Carbide on 65Mn Steel Used as Harrow Disk

2014 ◽  
Vol 1030-1032 ◽  
pp. 259-262 ◽  
Author(s):  
Hai Yang ◽  
Ren Bao Jiao ◽  
Shu Yang Wang
Keyword(s):  
Wear Resistance ◽  
Phase Composition ◽  
Tungsten Carbide ◽  
Sandy Soil ◽  
Surface Hardness ◽  
Working Life ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Hardness Tester ◽  
Carbide Layer

To improve the harrow disk made of 65Mn steel working life, an ion implanting metal in order to obtain tungsten carbide treatment was proposed in this work. Microstructure and phase composition of 65Mn steel obtained by ion implanting tungsten carbide process were analyzed by optical microscope and XRD, respectively. The surface hardness was tested by microscopic hardness tester, and the wear resistant performance of the wear layer was tested by abrader abrasor. The results showed that the micro-hardness of ion implanting tungsten carbide layer can be reached 1100 HV0.2, higher than that of 65Mn steel, the thickness of tungsten carbide layer was 400μm, which greatly improve the wear resistance. Harrow disk after the ion implanting tungsten carbide exhibited the excellent wear resistance in the sandy soil, and its working life was more than twice the length of the genera treatment harrow disk.

Influence of tungsten carbide particle size and distribution on the wear resistance of laser clad WC/Ni coatings

Wear ◽  
2005 ◽  
Vol 258 (1-4) ◽  
pp. 194-202 ◽  
Author(s):  
K. Van Acker ◽  
D. Vanhoyweghen ◽  
R. Persoons ◽  
J. Vangrunderbeek
Keyword(s):  
Particle Size ◽  
Wear Resistance ◽  
Tungsten Carbide ◽  
Carbide Particle

scholarly journals An in-vitro evaluation of mechanical and esthetic properties of orthodontic sealants

2014 ◽  
Vol 08 (04) ◽  
pp. 487-492 ◽  
Author(s):  
Thyagaseely Sheela Premaraj ◽  
Nima Rohani ◽  
David Covey ◽  
Sundaralingam Premaraj ◽  
Yi Hua ◽  
...  
Keyword(s):  
Particle Size ◽  
Wear Resistance ◽  
Surface Morphology ◽  
Wear Test ◽  
Color Stability ◽  
Micro Hardness ◽  
Wear Properties ◽  
Significant Difference ◽  
Sem Imaging

ABSTRACT Objective: To evaluate mechanical and esthetic Properties of two commercially available orthodontic sealants: Opal®Seal (OS) and L.E.D. Pro Seal (PS). Materials and Methods: Discs of each sealant were prepared to test the following properties: Micro hardness, wear resistance and color stability. Samples were randomly selected after the wear test for SEM imaging to analyze surface morphology. Results: OS was significantly harder than PS (P < 0.001). PS was significantly more wear resistant than OS (P < 0.05). PS showed a greater ΔE*ab (increased staining) when placed in wine or coffee showing a significant difference (P < 0.05). SEM showed particle size, shape and distribution were different for PS and OS reflecting the pattern seen on wear surfaces. Conclusion: Both orthodontic sealants are beneficial for protecting enamel. However with better wear properties PS was superior in resisting mechanical stresses. OS was more color stable.

COLMONOY No. 83 PTA

Alloy Digest ◽  
1995 ◽  
Vol 44 (12) ◽  
Keyword(s):  
Wear Resistance ◽  
Compressive Strength ◽  
Physical Properties ◽  
Tungsten Carbide ◽  
Tensile Properties ◽  
Powder Metal ◽  
Application Method ◽  
Plasma Transferred Arc ◽  
Transferred Arc ◽  
Nickel Base

Abstract COLMONOY No. 83 PTA is a nickel-base hard surfacing alloy containing tungsten carbide. The application method is plasma transferred arc and the application is designed to protect extrusion screws. This datasheet provides information on composition, physical properties, microstructure, hardness, tensile properties, and compressive strength. It also includes information on wear resistance as well as machining and powder metal forms. Filing Code: Ni-493. Producer or source: Wall Colmonoy Corporation.

Microstructure and Grain Abrasion Properties of Cr3C2-NiCr Coating Prepared by Laser Cladding Method

2012 ◽  
Vol 271-272 ◽  
pp. 3-7
Author(s):  
Long Wei ◽  
Zong De Liu ◽  
Xin Zhi Li ◽  
Ming Ming Yuan ◽  
Cheng Yuan Zhong
Keyword(s):  
Wear Resistance ◽  
Wear Rate ◽  
Laser Cladding ◽  
Micro Hardness ◽  
High Quality ◽  
Wear Resistant ◽  
Hardness Tester ◽  
Technology Analysis ◽  
Main Component

Cr3C2-NiCr has high quality of wear resistant properties and is widely used in abrasive environment. In this paper, Cr3C2-NiCr coating was prepared on 45 steel by laser cladding technology. Analysis and research of the coatings were achieved by SEM and XRD to determine the main component and the different region on coatings. The hardness and the element component were investigated by micro-hardness tester and EDS. Abrasion tests were performed to contrast the wear resistance of two materials. The results indicate that the hardness of the coatings is nearly 3 times as the substrate. The coatings are well combined with the substrate and the phase of Cr3C2 has a large proportion in the coatings. Abrasion tests show that the average of wear rate on substrate is 5.2 times as the coatings.

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