scholarly journals Defect Formation Mechanism and Performance Study of Laser Cladding Ni/Mo Composite Coating

Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1460
Author(s):  
Min Sun ◽  
Ming Pang
Keyword(s):  
Surface Layer ◽  
Composite Coating ◽  
Laser Cladding ◽  
Mixed Layer ◽  
Defect Formation ◽  
Surface Hardness ◽  
Scanning Speed ◽  
Performance Study ◽  
Cladding Layer ◽  
And Performance

In order to improve the wear resistance of Cu, a Ni/Mo composite coating was applied on the surface of Cu alloy by means of laser cladding. The laser power was 6000 W, the scanning speed was 5 mm/s and the feed rate was 10 g/min. The transition layer of the Ni layer had three layers, and the surface layer of the Mo layer had two layers. The results showed that the surface of the cladding layer was pure Mo. Due to the fluidity and non-equilibrium solidification of Mo in the molten state, pores and cracks along the grain boundary were observed in the Mo layer. The results showed that the cross-section of cladding layer was divided into a pure Mo layer, Mo-Ni-Cu mixed layer and an Ni-Cu mixed layer. The surface hardness of the Mo layer was 200~460 HV. Ni3Mo was formed at the interface of Mo and Ni. The hardness was improved by Ni3Mo; the maximum hardness was 750 HV. Under the same load and wear time, the wear rate of Cu was three times that of the surface layer.

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.

Influences of Processing Parameters on Dilution Ratio of Laser Cladding Layer during Laser Metal Deposition Shaping

2012 ◽  
Vol 549 ◽  
pp. 785-789 ◽  
Author(s):  
Kai Zhang ◽  
Xin Min Zhang ◽  
Wei Jun Liu
Keyword(s):  
Laser Cladding ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Metal Deposition ◽  
Laser Metal Deposition ◽  
Dilution Ratio ◽  
Factors Affecting ◽  
Cladding Layer ◽  
Performance Quality ◽  
And Performance

Laser Metal Deposition Shaping (LMDS) is a state-of-the-art technology that combines rapid prototyping and laser processing. There are many factors affecting the quality, precision, microstructure and performance of LMDS-deposited parts. Among them, dilution ratio is a significant one since it is not only an important index to judge the laser cladding quality, but directly affects the interlayer bonding strength and performance quality of as-formed metal parts. Thus, the substantial LMDS experiments were performed to conclude the influence of processing parameters on dilution ratio of laser cladding layer. The results indicate that the influence degree of scanning speed is most significant, while that of laser power is relatively slight. In order to ensure the perfect forming quality and strong metallurgical bonding, it is necessary to choose suitable dilution ratio to accomplish the LMDS process.

Microstructure and Hardness of the ZrO2/Ni60A Composite Coating Formed by Feeding Powder Laser-Clad on Circular Surface

2011 ◽  
Vol 138-139 ◽  
pp. 732-736
Author(s):  
Ba Sheng Ouyang ◽  
Run Juan You
Keyword(s):  
Laser Cladding ◽  
Ceramic Powder ◽  
Scanning Speed ◽  
Micro Hardness ◽  
Processing Property ◽  
Laser Process ◽  
Cladding Layer ◽  
Parameter Variations ◽  
Circular Surface ◽  
Cladding Layers

Cladding experiment with parameter variations was presented to manufacture the better processing property coating by laser cladding self-fused Ni-based ceramic powder of ZrO2 composite on the excircle surface of 304 SUS. The influence of the laser process parameters on macroscopic view, microstructure and micro-hardness of the laser cladding layers were investigated. The results show that we can get better coating when laser power is 1.5KW, and that the cladding layer microstructure has the trend of refined framework with the growing of scanning speed; micro-hardness will be higher and distribution from substratum to surface with little fluctuate by optimizing scanning speed.

Microstructures and Performance of Laser Cladding and Quenching Remanufactured Cladding Layer on QT700 Ductile Cast Iron Gear Surface

2021 ◽  
Vol 58 (5) ◽  
pp. 0514003-514003185
Author(s):  
陈世鑫 Chen Shixin ◽  
雷卫宁 Lei Weining ◽  
任维彬 Ren Weibin ◽  
薛冰 Xue Bing
Keyword(s):  
Cast Iron ◽  
Laser Cladding ◽  
Ductile Cast Iron ◽  
Cladding Layer ◽  
And Performance

Parameter optimisation of laser cladding repair for an Invar alloy mould

2018 ◽  
Vol 233 (8) ◽  
pp. 1859-1871 ◽  
Author(s):  
Shichao Zhu ◽  
Wenliang Chen ◽  
Xiaohong Zhan ◽  
Liping Ding ◽  
Junjie Zhou
Keyword(s):  
Dilution Rate ◽  
Laser Cladding ◽  
Laser Power ◽  
Scanning Speed ◽  
Advanced Technology ◽  
Invar Alloy ◽  
Geometric Features ◽  
Feeding Rates ◽  
Cladding Layer ◽  
Powder Feeding

Laser cladding repair is an advanced technology for repairing Invar alloy moulds; however, the influences of various processing parameters on the quality of the Invar alloy moulds have yet to be determined. To explore the optimisation of laser cladding repair parameters, analyses of the geometric features and microstructure of the cladding layer were conducted. First, the influences of different powder feeding rates and scanning speeds on the dilution rate of the substrate were investigated by establishing a mathematical model of the laser power attenuation. Next, the influences of the parameters on the geometric features of the cladding layer were analysed. Finally, the influences of the parameters on the microstructure of the cladding layer were evaluated. At a laser power of 2300 W, a scanning speed of 3 m/min, and a powder feeding rate of 9 g/min, the best results of the width, height, dilution rate, roughness, and contact angle of the cladding layer were obtained. The results of this study indicated that excellent metallurgical bonding occurred between the cladding layer and the interface layer, and that the intended geometric features and desired microstructure of the cladding layer were obtained.

Technology and Antimicrobial Properties of Cu/TiB2 Composite Coating on 304 Steel Surface Prepared by Laser Cladding

2019 ◽  
Vol 944 ◽  
pp. 473-479 ◽  
Author(s):  
Yu Sun ◽  
Vannghia Tran ◽  
Dao Zhang ◽  
Wen Bin Wang ◽  
Sen Yang
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Abrasion Resistance ◽  
Composite Coatings ◽  
Pure Copper ◽  
Antimicrobial Properties ◽  
Scanning Speed ◽  
Atomic Ratio ◽  
Ti Powder

In this study, Cu/TiB2composite coating was in-situ prepared on 304 steel by laser cladding. This coating applies to hospitals, schools and some public places where cross infections happen more easily because of its good antimicrobial properties and abrasion resistance. Before laser cladding, pre-blend of Cu powder, Ti powder and B powder were undertaken by ball-milling in two different proportions (10% wt (Ti+B) and 20% wt (Ti+B)). And the atomic ratio of Ti and B was 1:2. After a series of experiments, the best parameters were achieved. They were laser power (950W), scanning speed (14mm/s) and spot diameter (3.8mm). Samples after laser cladding were characterized using optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that TiB2was fabricated in-situ. The dispersion degree of Cu was higher in the coating of 20% wt (Ti+B). The hardness of the 10% wt (Ti+B) coating was HRC57±4. With the increase of percentage of wt (Ti+B), the hardness of 20% wt (Ti+B) coating was HRC74±5. Both of them performed better than pure copper. Relative to pure copper, the abrasion resistance of Cu/TiB2composite coatings was more excellent. The results of antimicrobial experiments showed that, with the increase of percentage of wt (Ti+B), the antimicrobial properties were decreasing. But they still could to be considered favorable.

Influence of Scanning Speed on Microstructure and Hardness during Laser Cladding High-Cr Cast Iron

2013 ◽  
Vol 395-396 ◽  
pp. 1127-1131 ◽  
Author(s):  
Wei Zhang
Keyword(s):  
Cast Iron ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Fish Bone ◽  
Cladding Layer ◽  
Metallurgical Bonding ◽  
Laser Scanning Speed ◽  
Gas Cavity ◽  
Cladding Layers

The experiments of laser cladding on the surface of 20 steel were made. High-chromium (Cr) cast iron powder was used as cladding material. The microstructure and hardness of laser cladding layers under different scanning speed were studied. The experiments showed that high-Cr cast iron cladding layer had better properties such as minute crystals, high density, no crack, no gas cavity and good metallurgical bonding with base metal. When the scanning speed was low, such as 10mm/min, the microstructure of cladding layer was cellular dendrite. There were much carbide with the shape of fish-bone distributing among cellular grains. Under higher scanning speed (from 100mm/min to 300mm/min), needle-shaped primary cementite would come into being. When laser scanning speed was 500mm/min, the carbide of cladding zone was very thin. With the increasing of laser scanning speed, the average hardness of cladding zone increased from 388HV0.2 to 580 HV0.2.

The Microstructure and Wear-Resistant Properties of Laser Cladding Ni-Based WC Alloy on Q345 Steel Surface

2014 ◽  
Vol 556-562 ◽  
pp. 189-192 ◽  
Author(s):  
Shun Min Zhu ◽  
Ya Dong Zhang
Keyword(s):  
Wear Resistance ◽  
Grain Refinement ◽  
Laser Cladding ◽  
Steel Surface ◽  
Surface Hardness ◽  
Wear Resistant ◽  
Cladding Layer

With the laser cladding technology, 70%Ni60A+30%WC cladding layer was cladded on the surface of Q345 steel. And the phase, microstructure and wear resistance of cladding layer were analyzed. Experiments show that the Ni-based WC alloy laser cladding treatment on Q345 steel surface have a great upgrade on grain refinement, surface hardness and wear-resistance of Q345 steel surface.

PREPARATION, MICROSTRUCTURE AND PERFORMANCE OF NANOSCALE CERAMICS REINFORCED HARD COMPOSITE COATING

2014 ◽  
Vol 21 (01) ◽  
pp. 1450004 ◽  
Author(s):  
PENG LI
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Sliding Wear ◽  
Rapid Heating ◽  
Dry Sliding Wear ◽  
Nanoscale Particles ◽  
Heating And Cooling ◽  
And Performance ◽  
First Time ◽  
Microstructure And Performance

This paper is based on the dry sliding wear of Stellite SF 12- B 4 C - TiN - Mo composite coating deposited on a pure Ti using a laser cladding technique, the parameters of which provide almost crack-free composites with low porosity. To the best of our knowledge, it is the first time that Stellite SF 12- B 4 C - TiN - Mo mixed powders are deposited as the hard composites by a laser cladding technique. Scanning electron microscope images indicate that the nanoscale particles are produced in such coating. The fact that due to the sufficiently rapid heating and cooling rates of the laser cladding technique, the ceramics, such as TiC or TiB 2 did not have enough time to grow up, resulting in the formation of the nanoscale particles. Compared with a pure Ti substrate, the increments of the micro-hardness and wear resistance are obtained for such composite coating.

Microhardness Analysis of Laser Cladding CBN Coating on the Surface of Titanium Alloy

2014 ◽  
Vol 551 ◽  
pp. 3-6
Author(s):  
Shu Guo Zhao ◽  
Xiao Min Yao ◽  
Rui Li
Keyword(s):  
Mechanical Property ◽  
Titanium Alloy ◽  
Boron Nitride ◽  
Laser Cladding ◽  
Laser Power ◽  
Cubic Boron Nitride ◽  
Scanning Speed ◽  
The Other ◽  
Micro Hardness ◽  
Cladding Layer

The Cubic boron nitride (CBN) coating are prepared by laser cladding on the TC11 surface.The hardness of cladding coating were researched by means of mechanical property testing.The result indicated that the coating micro-hardness increases with increasing laser power when the other parameters are fixed.With the laser power increasing,Injection of energy increases,The reinforced phase increased,microhardness along with it enhancement.With the increase of the scanning speed within chose, the microstructure of the cladding layer changes tiny and uniform,the microhardness were increased,The hardness was increased greatly which after Laser hardening. The maximum values of them are as about five times as that of the substrate.

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