scholarly journals Mechanical Properties of White Metal on SCM440 Alloy Steel by Laser Cladding Treatment

2021 ◽  
Vol 11 (6) ◽  
pp. 2836
Author(s):  
Jae-Il Jeong ◽  
Jong-Hyoung Kim ◽  
Si-Geun Choi ◽  
Young Tae Cho ◽  
Chan-Kyu Kim ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Alloy Steel ◽  
Laser Cladding ◽  
Laser Power ◽  
Centrifugal Casting ◽  
Operating Conditions ◽  
White Metal ◽  
X Ray ◽  
Friction Testing

The bearing is a machine element that plays an important role in rotating the shaft of a machine while supporting its weight and load. Numerous bearings have been developed to improve durability and life, depending on the functions and operating conditions in which they are desired. White metal is one of method to improve durability that is soft and bonded to the inner surface of the bearing to protect the bearing shaft. Currently, the centrifugal casting process is used as a white metal lamination method, but it involves problems such as long processing times, high defect rates and harmful health effects. In this paper, a laser cladding treatment is applied to bond powdered white metal to SCM440 alloy steel, which is used as bearing material in terms of replacing the risks of a centrifugal process. In order to understand whether laser cladding is a suitable process, this paper compares the mechanical properties of white metal produced on SCM440 alloy steel by centrifugal casting and the laser cladding process. The laser power, powder feed rate and laser head speed factors are varied to understand the mechanical properties and measure the hardness using micro Vickers and conduct field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction and friction testing to understand the mechanical properties and surface characteristics. Based on the results, the hardness values of the cladding (white metal) layer ranged between 24 and 26 HV in both the centrifugal casting and laser cladding methods. However, the hardness of the white metal produced by laser cladding at about a depth of 0.1 mm rose rapidly in the cladding process, forming a heat-affected zone (HAZ) with an average hardness value of 200 HV at a laser power of 1.1 kW, 325 HV at 1.3 kW and 430 HV at 1.5 kW. The surface friction testing results revealed no significant differences in the friction coefficient between the centrifugal casting and laser cladding methods, which allows the assumption that the processing method does not significantly influence the friction coefficient.

Influence of Curvature Radius of 40Cr on Mechanical Properties of Laser Cladding Layer

2018 ◽  
Author(s):  
Mingsan Xu ◽  
Kerstern Malama ◽  
Bingbing Li
Keyword(s):  
Mechanical Properties ◽  
Laser Cladding ◽  
Laser Power ◽  
Gas Flow ◽  
High Speed Steel ◽  
Scanning Speed ◽  
Structure Design ◽  
Curvature Radius ◽  
Metal Powders ◽  
Optimal Parameters

Laser cladding utilizes a high-powered laser to fuse and solidify the metal powders, which results in a complex change of physical and mechanical properties. Selection of parameters and creative structure design are critical for laser cladding technology. High-speed steel is cladded on the base metal 40Cr by diode laser to investigate the influence of curvature radius, scanning speed, gas flow and laser power. The micro hardness and residue stress are tested while the microstructure is analyzed. According to analysis of the process parameters in orthogonal experiment, the optimal parameters are: curvature radius 100 mm, laser power 1200W, gas flow 1000 L/h, and scanning speed 16 mm/s. Under the optimal parameters, the microstructure and grid is uniform and the grain growth is along the same direction.

scholarly journals The Effect of Laser Power on the Properties of M3B2-Type Boride-Based Cermet Coatings Prepared by Laser Cladding Synthesis

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1867 ◽  
Author(s):  
Zhaowei Hu ◽  
Wenge Li ◽  
Yuantao Zhao
Keyword(s):  
Laser Cladding ◽  
Laser Power ◽  
Chemical Properties ◽  
Scanning Speed ◽  
Carbon Steels ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Cermet Coatings ◽  
X Ray ◽  
And Chemical Properties

Boride-based cermet can serve as a good protective coating for low-corrosion and wear-resistant materials, such as carbon steels, due to their mechanical and chemical properties. In this study, M3B2 (M: Mo, Ni, Fe, and Cr) boride-based cermet coatings were fabricated on Q235 steel with mixed powders of Mo, B, Ni60, and Cr by laser cladding synthesis, and the effects of laser power on the properties of the cermet layer were investigated. Three laser powers (2200, 2500, and 2800 W) were used at the same scanning speed. The X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) analysis confirmed that all the coatings were composed of M3B2-type borides and {Fe, Ni} alloys. The micro-hardness, corrosion, and frictional experiments showed that the cermet coatings enhanced the corresponding performances of the Q235 steels at the three laser powers. However, the micro-hardness of the coatings decreased as the power increased, and the maximum micro-hardness value was 1166.3 HV (Vickers Hardness). The results of the corrosion and frictional experiments showed that the best performance was obtained at a laser power of 2500 W, followed by 2800 and 2200 W.

scholarly journals Preparation and the Mechanical and Tribological Properties of Laser Cladding Coating

2021 ◽  
Vol 2083 (2) ◽  
pp. 022067
Author(s):  
Xin Zhou ◽  
Yanjun Wang ◽  
Lei Liu ◽  
Xingju Guo
Keyword(s):  
Friction Coefficient ◽  
Laser Cladding ◽  
Laser Power ◽  
Friction And Wear ◽  
Steel Substrate ◽  
Alloy Coating ◽  
Coated Sample ◽  
Dilution Ratio ◽  
Mechanical And Tribological Properties ◽  
Hardness Tester

Abstract laser cladding of snsbcu based alloy coating on GCr15 steel substrate was carried out by using lam-400s powder feeding metal printer. The hardness, friction coefficient and microstructure of the coating were tested by Vickers hardness tester, friction and wear tester, metallographic microscope and scanning electron microscope. The effects of laser cladding parameters on the dilution ratio, hardness and friction coefficient of the sample were studied; With the increase of laser power, the hardness of the coating is improved, and the hardness distribution is more uniform; The friction coefficient of the coated sample decreases greatly compared with that of the substrate.

Influence of carbon nanotubes on the properties of friction composite materials

2019 ◽  
Vol 54 (16) ◽  
pp. 2101-2111
Author(s):  
Emad F EL-kashif ◽  
Shaimaa A Esmail ◽  
Omayma AM Elkady ◽  
BS Azzam ◽  
Ali A Khattab
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Smart Materials ◽  
Arc Discharge ◽  
Weight Ratio ◽  
Friction Material ◽  
Operating Conditions ◽  
Friction Materials

Carbon nanotubes have a lot of applications in mechanical fields. This is because nanomaterials have many superior mechanical properties such as very high strength-to-weight ratio, high modulus-to-weight ratio, high corrosion resistance, and super intelligence properties, which make them as smart materials. One of these attractive applications is the use of carbon nanotubes in vehicle brake friction material. Therefore, the fabrication and testing processes of these nanomaterials should be performed carefully to evaluate their mechanical, tribological, and noise properties. In this paper, friction material mixed with carbon nanotubes have been fabricated with different carbon nanotube contents and the same fabrication parameters. The carbon nanotubes have been produced using the conventional submerged arc discharge technique. The produced friction materials have been cut into pieces with standard sizes and then tested mechanically and tribologically. The results of tests have illustrated that the addition of carbon nanotubes into the friction materials could improve their mechanical properties (hardness, strength, and modulus) and also could enhance their tribological properties (wear rate and friction coefficient). Moreover, the tests showed that the presence of carbon nanotubes in friction materials could reduce the noise, vibration of the friction materials, and reduce the temperature rise due to the effect of friction, which means that the carbon nanotubes could raise the thermal conductivity of friction material, while the friction coefficient has stayed within the allowable standard limits (0.35–0.45). Surface morphology shows that the presence of carbon nanotubes in the friction materials could help to avoid surface friction cracks or fins within the normal operating conditions. The good combination of mechanical and tribological properties was obtained at 0.5% carbon nanotubes.

The Microstructure and Properties of Restored WCP/Fe-C Composites

2011 ◽  
Vol 194-196 ◽  
pp. 2105-2108
Author(s):  
Yan Pei Song ◽  
Hui Gai Wang
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Centrifugal Casting ◽  
X Ray Diffraction ◽  
Casting Method ◽  
X Ray ◽  
Microstructure And Properties

A restored WCP/Fe-C composites is manufactured by centrifugal casting method. The microstructure and properties of the restored composites have been investigated by SEM, X-ray diffraction and properties tester. The results show that the distribution of WCP in the restored composites is even, Size of WCP is obviously reduced, and their volume fraction attained to about 70 vol.%. The mechanical properties and wear behavior of the restored composites are almost the same as those of the primary composites.

scholarly journals Microstructure and Wear Properties of Laser Cladding WC/Ni-Based Composite Layer on Al–Si Alloy

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5288
Author(s):  
Xiaoquan Wu ◽  
Daoda Zhang ◽  
Zhi Hu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Laser Cladding ◽  
Energy Dispersive Spectrometer ◽  
Composite Layer ◽  
Wear Testing ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray ◽  
Original Specimen

The microstructural and wear properties of laser-cladding WC/Ni-based layer on Al–Si alloy were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), energy dispersive spectrometer (EDS) and wear-testing. The results show that, compared with the original specimen, the microhardness and wear resistance of the cladding layer on an Al–Si alloy were remarkably improved, wherein the microhardness of the layer achieved 1100 HV and the average friction coefficient of the layer was barely 0.14. The mainly contributor to such significant improvement was the generation of a WC/Ni-composite layer of Al–Si alloy during laser cladding. Two types of carbides, identified as M7C3 and M23C6, were found in the layer. The wear rate of the layer first increased and then decreased with the increase in load; when the load was 20 N, 60 N and 80 N, the wear rate of layer was1.89 × 10−3 mm3·m−1, 3.73 × 10−3 mm3·m−1 and 2.63 × 10−3 mm3·m−1, respectively, and the average friction coefficient (0.14) was the smallest when the load was 60 N.

scholarly journals Wear Behaviors of TiN/WS2 + hBN/NiCrBSi Self-Lubricating Composite Coatings on TC4 Alloy by Laser Cladding

Coatings ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 747
Author(s):  
Kaiwei Liu ◽  
Hua Yan ◽  
Peilei Zhang ◽  
Jian Zhao ◽  
Zhishui Yu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Friction Coefficient ◽  
Composite Coating ◽  
Laser Cladding ◽  
Sliding Wear ◽  
Composite Coatings ◽  
Wear Test ◽  
Dry Sliding Wear ◽  
X Ray ◽  
Tc4 Alloy

TiN and WS2 + hBN reinforced Ni-based alloy self-lubricating composite coatings were fabricated on TC4 alloy by laser cladding using TiN, NiCrBSi, WS2, and hBN powder mixtures. Energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffractometry (XRD), and optical microscopy (OM) were adopted to investigate the microstructure. The wear behaviors of the self-lubricating composite coatings were evaluated under large contact load in room temperature, dry-sliding wear-test conditions. Results indicated that the phases of the coatings mainly include γ-Ni, TiN, TiNi, TiW, WS2, and TiS mixtures. The average microhardness of the composite coating is 2.3–2.7 times that of the TC4 matrix. Laser cladding TiN/WS2 + hBN/NiCrBSi self-lubricating composite coatings revealed a higher wear resistance and lower friction coefficient than those of the TC4 alloy substrate. The friction coefficient (COF) of the coatings was oscillating around approximately 0.3458 due to the addition of self-lubricant WS2 + hBN and hard reinforcement TiN. The wear behaviors testing showed that the wear resistance of the as-received TC4 was significantly improved by a laser cladding TiN/WS2 + hBN/NiCrBSi self-lubricating composite coating.

MICROSTRUCTURE AND WEAR PROPERTIES OF COMPOSITE COATINGS PRODUCED BY LASER CLADDING OF Ti-6Al-4V WITH GRAPHITE AND SILICON MIXED POWDERS

2005 ◽  
Vol 12 (02) ◽  
pp. 161-165 ◽  
Author(s):  
Y. S. TIAN ◽  
C. Z. CHEN ◽  
D. Y. WANG ◽  
Q. H. HUO ◽  
T. Q. LEI
Keyword(s):  
Titanium Alloy ◽  
Friction Coefficient ◽  
Laser Cladding ◽  
Energy Dispersive Spectroscopy ◽  
Composite Coatings ◽  
Transitional Zone ◽  
Test Results ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray

Composite coatings are fabricated by laser cladding of titanium alloy Ti-6Al-4V with graphite and silicon mixed powders. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) indicate that the coatings mainly consist of pre-eutectic TiC and eutectic Ti 5 Si 3 compounds. Test results show that the coatings exhibit a higher microhardness and a lower friction coefficient compared with the as-received sample. EPMA micrographs show that the compounds' morphology in the top zone of the coatings is different from that in the transitional zone.

Effect of Powder Size and Volume Fraction of WC on the Microstructure of Laser Cladding WC-NiCrBSi Composite Coatings

2011 ◽  
Vol 121-126 ◽  
pp. 105-109
Author(s):  
Y.Y. Wang ◽  
Y.F. Gong ◽  
T.F. Sun ◽  
P.F. Ni ◽  
Z. Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Laser Cladding ◽  
Laser Power ◽  
Volume Fraction ◽  
Composite Coatings ◽  
Nonuniform Distribution ◽  
Powder Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

WC-NiCrBSi composite coatings on 0.45 % carbon steel were fabricated by laser cladding. The volume fraction (33, 43 and 60 vol. %) of WC particles with the powder size of 2 μm, 5 μm and 50 μm were added respectively into NiCrBSi powders to deposit composite coatings. The microstructure of the powders and the coatings were examined by scanning electron microscope (SEM) and X-ray diffraction (XRD). Results show that the compactness and uniformity of the coatings are good when WC particles size was 2 μm and 5 μm. However nonuniform distribution and deposit of WC particles on the bottom of the coating will occur when the powder size of WC particles was 50 μm and the volume fraction of WC was 33 %. When the volume of WC addition was higher than 60 %, the volume fraction of the retained WC particles in the coatings is obviously decreased. The dissolving and decomposing of WC increase with decreasing the powder size and increasing the volume of WC addition and the laser power.

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