scholarly journals The Effect of Laser Power on the Interface Microstructure of a Laser Remelting Nano-SiC Modified Fe-Based Ni/WC Composite Coating

Coatings ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 297 ◽  
Author(s):  
Yuncai Zhao ◽  
Wen He ◽  
Huihui Du ◽  
Peng Luo
Keyword(s):  
Composite Coating ◽  
Laser Power ◽  
Intermediate Phase ◽  
Composite Coatings ◽  
Peak Height ◽  
Interface Microstructure ◽  
Laser Remelting ◽  
General Terms ◽  
Sic Particles ◽  
Average Grain Size

The plasma sprayed Fe-based Ni/WC composite coating on the surface of 45 steel was post-treated by laser remelting with the addition of nano-SiC. The effect of laser power on the interface microstructure of a laser remelting nano-SiC modified Fe-based Ni/WC composite coatings were researched. The metallographic structure, microscopic morphology, phase composition, and microhardness of the remelted layer were visually analyzed by metallographic microscope, scanning electron microscope (SEM), X-ray diffractometer (XRD), and microhardness tester, respectively. The results showed that the nano-SiC modified remelted coating was smooth and compact, and with no fine cracks. The remelted layer was mainly composed of [Fe,Ni], Cr, Fe0.04Ni0.36 phase. The metal elements Fe, Ni, Cr, and Si, and non-metallic element C, appeared to diffuse, and there was metallurgical bonding between the coating and the matrix. With the increase of laser power, the smaller the average grain size, the wider the half-peak height (FWHM), and the more obvious the grain refinement. When the laser power was 500 W, the interface metallurgical showed the best effect. Furthermore, the nano-sized SiC particles served as the core of the heterogeneous nucleation to refine the grains on the one hand, and promoted the formation of a hard intermediate phase in the coating on the other hand. Therefore, the laser remelting and the addition of nano-SiC particles greatly improved the microhardness of the coating. The larger the laser power, the smaller the microstructure characteristics and the fewer the number of holes. With increasing laser power, the hardness increased in general terms and the maximum hardness increased by 51%.

Hardness Regulation of Fe-Based Amorphous Composite Coatings by Laser Remelting

2014 ◽  
Vol 789 ◽  
pp. 64-69 ◽  
Author(s):  
Yong Tian Wang ◽  
Ming Ming Yuan ◽  
Jing Kang Duan ◽  
Run Sen Jiang ◽  
Lin Hu ◽  
...  
Keyword(s):  
Composite Coating ◽  
Laser Power ◽  
Volume Fraction ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Power Input ◽  
Arc Spraying ◽  
Laser Remelting ◽  
Application Fields

A Fe-based amorphous composite coating was deposited on a carbon steel substrate by arc spraying, and remelted with different laser energies by the Nd: YAG laser cladding system, in order to improve the mechanical properties of the coatings. The microstructure and microhardness of the composite coatings were investigated. The variation of harndness was measured as a function of the modified layer depth, which indicates that the laser remelting improves the bonding strength and hardness. Increasing the laser power, the quality of coating gets better, but the amorphous volume fraction decreases. It is obtained that the optimal laser electric current for the coating of 280 μm thickness is about 300 A, in which the remelted coating with medium energy densities has the highest average Vickers hardness of 741. Through the volume fraction change of the nanocrytals, the hardness of the composite coating is regulated by the laser power input, which amplified the application fields of the amorphous coatings.

Research on the Fabrication of Bioceramic Composite Coatings Fabricated by Nd-YAG Laser Cladding

2015 ◽  
Vol 723 ◽  
pp. 852-855
Author(s):  
Ying Chun Wang ◽  
Xiang Fei Lv ◽  
Deng Jie Zhu ◽  
Shao Min Qu
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
New Technology ◽  
Scanning Speed ◽  
Processing Technique ◽  
Yag Laser ◽  
Cladding Layer ◽  
Ti6al4v Substrate ◽  
Average Grain Size

Laser surface cladding is a material processing technique to overlay the precursor material with the substrate to form a sound chemical and metallurgical bonding. Recently, laser cladding technique has been introduced in the bioceramic coating field. This paper presents a new technology to obtain bioceramic composite coating on Ti6Al4V substrate by Nd-YAG laser cladding. The microstructures of the mixed powders and cladding layer were investigated by scanning electron microscopy, and the compositions were analyzed by electron diffraction spectroscopy. The phases of the mixed powders and cladding layer were clarified by X-ray diffraction technology. Composite coating including HAP,Ca2P2O7,Ca3(PO4)2 and calcium titanates was successfully obtained by Nd-YAG laser cladding with pre-depositing mixed powders of CaHPO4·2H2O and CaCO3 directly on Ti6Al4V substrate. The average grain size of the mixed powders is 3μm from the image analyse software. The most important parameter that affected the completion of laser cladding was the scanning speed.

Microstructure and Wear Behavior of SiCP-Reinforced Magnesium Matrix Composite by Cold Spraying

2011 ◽  
Vol 314-316 ◽  
pp. 253-258
Author(s):  
Xin Kun Suo ◽  
Xue Ping Guo ◽  
Wen Ya LI ◽  
Marie Pierre Planche ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Composite Coating ◽  
Wear Behavior ◽  
Composite Coatings ◽  
Cold Spraying ◽  
Test System ◽  
Magnesium Matrix ◽  
Sic Particles ◽  
Sliding Test ◽  
Sprayed Coatings ◽  
Ball On Disc

In this paper, dense AZ91D/SiC composite coatings were fabricated by cold spraying. The microstructure and microhardness of the as-sprayed coatings were investigated. The results show that the content of SiC particles in the composite coating was 23.6 ± 7.5 vol.%. The microhardness of the composite coating was improved to 140 HV0.3 due to the enhancement of SiC particles, compared to 98 HV0.3 for the pure AZ91D coating. The wear behavior of the composite coating in an ambient condition was studied through a ball-on-disc dry sliding test system. The composite coating showed higher friction coefficient and lower wear rate than the pure AZ91D coating. The wear mechanism of the composite coating was discussed.

Preparation and Numerical Simulation of Ni-SiC Composite Coatings Deposited by Electrodeposition

2014 ◽  
Vol 543-547 ◽  
pp. 3707-3710
Author(s):  
Yong Wang ◽  
Lei Zhang
Keyword(s):  
Composite Coating ◽  
Current Density ◽  
Pulse Current ◽  
Composite Coatings ◽  
Maximum Error ◽  
Duty Ratio ◽  
Sic Particles ◽  
Ultrasonic Parameters ◽  
Steel Substrates ◽  
Sic Coatings

In order to investigate and predict effects of preparation parameters on wear mass loss of Ni-SiC composite coatings, Ni coatings and Ni-SiC composite coatings were prepared on steel substrates by electrodeposition process. The results showed that the contents of SiC particles increased with density of pulse current and on-duty ratio of pulse current increasing. The predictive curves of wear mass losses predicted by ANN had the similar shapes with the measured curve, and the maximum error was 9.7%. When the current density was between 30 A/dm2 and 50 A/dm2, the wear losses of Ni coatings and Ni-SiC coatings decreased with the increase of current density. SiC particles in a composite coating electrodeposited by ultrasonic parameters were much greater in number and were dispersed homogeneously in the deposit, and the Ni-SiC composite coating exhibited a dense structure.

Preparation and Characterization of Plasma-Sprayed and Laser-Remelted Ni60/Ni-WC Coatings

2014 ◽  
Vol 540 ◽  
pp. 17-20
Author(s):  
Dong Sheng Wang
Keyword(s):  
Laser Power ◽  
Composite Coatings ◽  
Microstructural Characterization ◽  
Matrix Alloy ◽  
Laser Remelting ◽  
Base Matrix ◽  
High Microhardness ◽  
Sprayed Coating ◽  
Plasma Sprayed

In this study, Ni60/Ni-WC composite coatings were first prepared by plasma spraying. Then, the coatings were remelted successively with a CO2 laser. The influences of laser power on the microstructural characterization and microhardness of the coatings were investigated. The results show that the defects of as-sprayed coating like lamellar stacking microstructure and pores were eliminated by laser remelting, and the remelted coating possessed a denser microstructure. With the increase of the laser power, the burning loss and dissolve of the WC particles is increased, while the dilution rate of the coating becomes large. The laser-remelted samples had higher hardness than the as-sprayed one. Laser power has a great impact on the coating and an optimized process parameter is helpful to achieve appropriate melting of WC particles, which leads to retain a high proportion of hard phase in the coating, good combination between the WC particles and Ni-base matrix alloy, and high microhardness.

An Experimental Study on the Properties of Fe-Based Amorphous Composite Coatings Prepared by Different Processes

2011 ◽  
Vol 239-242 ◽  
pp. 2137-2141 ◽  
Author(s):  
De Juan Xie ◽  
Zong De Liu ◽  
Wei Qiang Hu ◽  
Yong Tian Wang
Keyword(s):  
Composite Coatings ◽  
Arc Spraying ◽  
Water Cooling ◽  
Micro Hardness ◽  
Laser Remelting ◽  
Structure Defects ◽  
Hardness Tester ◽  
Metallurgical Bonding ◽  
Average Grain Size ◽  
Hardness Values

Fe-based amorphous composite coatings were deposited on the surface of ASTM-1020 steel plate by different technologies: arc spraying, laser remelting, TIG remelting (with and without water cooling). The microstructure, phase structure and micro-hardness were characterized by using a combination of SEM, XRD and Vickers hardness tester. It shows that the coating prepared by arc spraying presents typical lamellar structure and poor adherence to the substrate. After the remelting treatment, the coating quality is significantly improved by decreasing structure defects such as cracks and pores; the interface shows the metallurgical bonding. The dendritic crystals could be obtained within all the remelted coatings with different appearances. The microstructures of TIG remelted coatings show much more regular and have obvious orientation, which cannot be seen in laser remelted coating. However, the average grain size of the laser remelted coating is much smaller than that of TIG remelted coatings. The micro-hardness values of all of the deposited coatings are much higher than that of the substrate, and the coating prepared by laser remelting shows the highest hardness.

Effects of the Additives and Current Density on the Electrodeposition Behavior and Mechanical Properties of the Ni-SiC Composite Coatings

2007 ◽  
Vol 345-346 ◽  
pp. 1533-1536 ◽  
Author(s):  
Teck Su Oh ◽  
Jae Ho Lee ◽  
Ji Young Byun ◽  
Tae Sung Oh
Keyword(s):  
Mechanical Properties ◽  
Sulfuric Acid ◽  
Composite Coating ◽  
Surface Properties ◽  
Current Density ◽  
Composite Coatings ◽  
Cross Sectional ◽  
Sic Particles ◽  
Current Densities ◽  
Sulfamate Bath

In Ni-SiC composite coating, the SiC content is dependent on the surface properties of SiC particles. As sulfuric acid has a strong dehydration force, addition of sulfuric acid in the Ni sulfamate bath changed the surface properties of SiC particles, affecting the codeposition behavior of SiC particles. Also the additives such as SDS affect the electrodeposition behavior of the Ni-SiC composite coating. In this study, effects of the HSO4 ‾ and the current density on the electrodeposition behavior of the Ni-SiC composite coating have been investigated. The Ni-SiC composite coatings were electrodeposited at current densities of 50~200mA/cm2. The surface and cross-sectional morphologies of the Ni-SiC composite coatings were observed using SEM, and their mechanical properties were characterized with micro-Vikers hardness.

Effect of variation in SiC loading, current density and bath temperature on coating thickness and tensile strength of Ni-SiC nanocomposite coatings

2013 ◽  
Vol 10 (6) ◽  
pp. 515-522
Author(s):  
K. Sharma ◽  
A. Seethagirisha
Keyword(s):  
Tensile Strength ◽  
Composite Coating ◽  
Current Density ◽  
Coating Thickness ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Bath Temperature ◽  
Experimental Results ◽  
Sic Particles ◽  
Sic Coatings

The mechanical properties like hardness, tensile strength, wear resistance of electro-co-deposited Ni-SiC coatings are dependent on factors like bath temperature, current density, duration of deposition, amount of SiC particles etc. Ni-SiC nano composite coatings were prepared on a mild steel substrate by electro-co-deposition process. In this study, the effect of electrochemical bath parameters such as bath temperature, current density and SiC loading were varied and effect of this variation on the coating thickness and tensile strength of Ni-SiC composite coating was studied. The experimental results showed that, a uniform deposit thickness was obtained for 3 A/dm2 current density, temperature of 55°C and loading of 4 g/l. A peak value of coating thickness was observed at a current density of 4 A/dm2 from the experiment. The experimental results also showed that, the tensile strength of the composite coating containing SiC the is significantly higher than pure Ni coating and the tensile strength increases with an increase in the percentage of SiC particles in Ni-SiC coatings. The tensile strength of the composite coating increased by nearly about 52% with increasing SiC loading and then decreased.

scholarly journals Effect of Scanning Speed on the Interface Behavior and Dendrite Growth of Laser Remelted Fe-Based Ni/WC Coatings

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 677 ◽  
Author(s):  
Yuncai Zhao ◽  
Li Wang ◽  
Wen He
Keyword(s):  
Grain Size ◽  
Scanning Speed ◽  
Peak Height ◽  
Element Distribution ◽  
Laser Remelting ◽  
Interface Behavior ◽  
Metallurgical Bonding ◽  
Average Grain Size ◽  
Mechanical Bonding ◽  
Interface Behaviour

The flame sprayed Fe-based Ni/WC cermet coating was treated by laser remelting. The influence of scanning speeds on the interface behaviour was investigated. SEM, XRD and EDS were used to analyse the microstructure, phase composition and element distribution of the interface. The results showed that the interface of the coating contained holes and interlayer cracks and showed typical mechanical bonding features. The coatings mainly consisted of [Fe, Ni], Cr, WC, Cr7C3, Fe0.04Ni0.36, and other phases. After laser remelting, the coatings were smooth and dense due to the existence of well-developed dendrite structures and metallurgical bonding and could reach the optimal performance at 200 mm/s. New phases such as Fe2Si, Cr2Si, and W2C appeared in the remelted layers. With the increase of scanning speed, the half-peak height and average grain size became wider and smaller. At the same time, the measured dendrite spacing decreased with increasing scanning speed.

scholarly journals SiCp/Al5056 Composite Coatings Applied to A Magnesium Substrate by Cold Gas Dynamic Spray Method for Corrosion Protection

Coatings ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 325 ◽  
Author(s):  
Yingying Wang ◽  
Bernard Normand ◽  
Hanlin Liao ◽  
Guofeng Zhao ◽  
Nicolas Mary ◽  
...  
Keyword(s):  
Thermal Cycling ◽  
Composite Coating ◽  
Corrosion Protection ◽  
Galvanic Corrosion ◽  
Composite Coatings ◽  
Cold Spraying ◽  
Corrosion Properties ◽  
Sic Particles ◽  
Cold Gas Dynamic Spray ◽  
Average Size

Corrosion protection using cold spraying is a promising method to address the shortcomings associated with classical techniques for protecting magnesium alloys from corrosion. In this study, SiCp/Al 5056 composite coatings were prepared on a magnesium substrate using cold spraying. The effects on the microstructure and corrosion properties after adding SiC were analysed. To evaluate the durability of the cold-sprayed Al-based coatings on Mg, galvanic corrosion, immersion and thermal cycling tests were conducted. The results show that cold-sprayed aluminium coatings serve as a reliable cathode for magnesium substrates. The addition of SiC particles increases the galvanic potential and decreases the galvanic reduction current of the coating/substrate couple. The SiCp/Al 5056 composite coatings show better corrosion resistance than that of the Al 5056 coating in extended immersion tests due to the densification of the coating under the peening effect of hard particles. Moreover, SiC particles with an average size of 15.6 µm show more improvement than with SiC particles having an average size of 72.8 µm. The cold-sprayed SiCp/Al 5056 composite coating also presents excellent properties in the thermal cycling tests. After applying failure mode parameters in the thermal cycling tests, the composite coating demonstrates good adhesion as cracking was located in the Mg substrate and not at the interface.

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