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.

Bioceramic Composite Coatings Fabricated by Nd-YAG Laser Cladding Process on Ti6Al4V Substrate

2012 ◽  
Vol 198-199 ◽  
pp. 68-71 ◽  
Author(s):  
Ying Chun Wang ◽  
Yu Yong Yang ◽  
Mei Chun Wang
Keyword(s):  
Calcium Phosphate ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Mechanism Analysis ◽  
Yag Laser ◽  
Ti6al4v Substrate ◽  
Metallurgical Bonding ◽  
Laser Cladding Process ◽  
Modification Procedure

Laser cladding technology was adopted to fabricate hydroxyapatite(HAP) and calcium phosphate compound coating according to the feature that a metallurgical bonding can be formed by laser cladding process. Compared with CO2laser, Nd-YAG laser has different wavelength(the former is 1.06μm and the latter is 10.06μm). Metal and ceramic material has quite different absorbance ability towards them and thus they can generate different laser cladding products by these two laser surface processings with different wavelength. This paper presents a new process and mechanism analysis to obtain bioceramic composite coating on Ti6Al4V substrate by Nd-YAG laser cladding. A bioceramic composite coating including HAP，Ca2P2O7，Ca3(PO4)2and calcium titanates and was successfully obtained by Nd-YAG laser cladding with pre-depositing mixed powders of CaHPO4•2H2O and CaCO3directly on Ti6Al4V substrate. Nd-YAG laser transmits mixed powders of CaHPO4•2H2O and CaCO3and the laser power is absorbed by Ti6Al4V substrate to produce a thin layer of molten region. There are mainly two kinds of chemical reaction systems in the coating during laser cladding processing. When CaHPO4•2H2O and CaCO3react together, they make calcium phosphate bioceramic products; The microstructure of the bioceramic composite coating is even and minute because of the rapid solidification in laser processing. A chemical metallergical bonding is formed between the boceramic composite coating and Ti6Al4V substrate. It can also be expected that Nd-YAG laser cladding technology can be used as a further modification procedure to enhance HAp/metal interface property.

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.

scholarly journals Microstructures and Wear Resistance of FeCoCrNi-Mo High Entropy Alloy/Diamond Composite Coatings by High Speed Laser Cladding

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 300 ◽  
Author(s):  
Haijiang Wang ◽  
Wei Zhang ◽  
Yingbo Peng ◽  
Mingyang Zhang ◽  
Shuyu Liu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
High Speed ◽  
Composite Coatings ◽  
Scanning Speed ◽  
High Entropy Alloy ◽  
Dilution Ratio ◽  
High Entropy ◽  
High Scanning Speed

FeCoCrNi-Mo high entropy alloy/diamond composite coatings were successfully prepared by high speed laser cladding. A high scanning speed was adopted (>30 mm/s), and the effects of laser power, scanning speed, and diamond content on the microstructure and wear resistance of the composite coating were studied. The processing parameters of laser cladding had significant influence on the dilution ratio, graphitization of diamond, and wear resistance of the composite coatings. When the laser cladding parameters were 3000 W of laser power and the high scanning speed of 50 mm/s, the composite coating exhibited a uniform microstructure, the lowest dilution ratio, and the best wear resistance. The wear resistance of the composite coating was enhanced with the addition of diamond, but microcracks also increased. When the amount of diamond was 15 wt.%, the best combination of microstructures and wear resistance was obtained.

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.

SYNTHESIS AND CHARACTERIZATION OF Zr-BASED AMORPHOUS AND CRYSTALLINE COMPOSITE COATING ON Ti SUBSTRATE BY LASER CLADDING

2014 ◽  
Vol 21 (01) ◽  
pp. 1450007 ◽  
Author(s):  
D. M. TANG ◽  
D. C. ZHANG ◽  
W. PENG ◽  
Z. C. LUO ◽  
X. Q. WU ◽  
...  
Keyword(s):  
Composite Coating ◽  
Amorphous Phase ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Raw Material ◽  
Thin Strip ◽  
Beam Diameter ◽  
Laser Scanning Speed

A thin strip of a Zr -based alloy with a composition of Zr 60 Cu 25 Fe 5 Al 10 (in atom percent) was used as a raw material, and the composite coatings containing Zr -based amorphous phase and crystallites on Ti substrate were fabricated by a one-step laser cladding method without protection. The microstructure, phase constitution, microhardness and wear properties of the coatings were investigated. The results indicate that the microstructure of the coatings is strongly dependent on the laser scanning speed under the conditions of the laser power of 1300 W and laser beam diameter of 6 mm, and the composite coating mainly containing amorphous phase with a small amount of the crystallites can be obtained at the laser scanning speed of 10 mm/s. The composite coating exhibits much higher microhardness than the pure Ti substrate, and thus it behaves superior wear resistance in comparison with the substrate.

scholarly journals Isothermal Oxidation Performance of Laser Cladding Assisted with Preheat (LCAP) Tribaloy T-800 Composite Coatings Deposited on EN8

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 843
Author(s):  
Sipiwe Trinity Nyadongo ◽  
Sisa Lesley Pityana ◽  
Eyitayo Olatunde Olakanmi
Keyword(s):  
Iron Oxide ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Parabolic Rate Constant ◽  
Mass Gain ◽  
Isothermal Oxidation ◽  
Operational Parameters ◽  
Temperature Oxidation ◽  
Service Environments

It is anticipated that laser cladding assisted with preheat (LCAP)-deposited Tribaloy (T-800) composite coatings enhances resistance to structural degradation upon exposure to elevated-temperature oxidation service environments. The oxidation kinetics of LCAP T-800 composite coatings deposited on EN8 substrate and its mechanisms have not been explored in severe conditions that are similar to operational parameters. The isothermal oxidation behaviour of the T-800 composite coating deposited on EN8 via LCAP was studied at 800 °C in air for up to 120 h (5 × 24 h cycles) and contrasted to that of uncoated samples. The mass gain per unit area of the coating was eight times less than that of the uncoated EN8 substrate. The parabolic rate constant (Kp) for EN8 was 6.72 × 10−12 g2·cm−4·s−1, whilst that for the T-800 composite coating was 8.1 × 10−13 g2·cm−4·s−1. This was attributed to a stable chromium oxide (Cr2O3) layer that formed on the coating surface, thereby preventing further oxidation, whilst the iron oxide film that formed on the EN8 substrate allowed the permeation of the oxygen ions into the oxide. The iron oxide (Fe2O3) film that developed on EN8 spalled, as evidenced by the cracking of oxide when the oxidation time was greater than 72 h, whilst the Cr2O3 film maintained its integrity up to 120 h. A parabolic law was observed by the T-800 composite coating, whilst a paralinear law was reported for EN8 at 800 °C up to 120 h. This coating can be used in turbine parts where temperatures are <800 °C.

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.

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.

scholarly journals Laser Cladding of Ni-Co-W Composite Coating on Stainless Steel to Enhance Wear Resistance

2021 ◽  
Author(s):  
Linlin ZHANG ◽  
Dawei ZHANG
Keyword(s):  
Stainless Steel ◽  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Eutectic Structure ◽  
Wear Properties ◽  
Fine Grained ◽  
Noticeable Improvement ◽  
Enhance Wear Resistance

Ni-Co-W composite coatings modified by different contents of Co-based alloy powder in the Ni-based alloy with 35 wt.% WC (Ni35WC) were deposited on stainless steel by laser cladding. The influence of compositional and microstructural modification on the wear properties has been comparatively investigated by XRD, SEM, and EDS techniques. It was found that the austenite dendrites in the modified coating adding 50 wt.% Co-based alloy were refined and a lot of Cr23C6 or M23(C, B)6 compounds with fine lamellar feature were formed around austenitic grain boundaries or in the intergranular regions. The contribution of element Co to the modification of Ni35WC coating is that it cannot only promote the formation of more hard compounds to refine austenite grains, but also refine the size of precipitates, and change the phase type of eutectic structure as a result of disappeared Cr boride brittle phases. A noticeable improvement in wear resistance is obtained in the Ni35WC coating with 50 wt.% Co-based alloy, which makes the wear rate decreased by about 53 % and 30% by comparison to that of the substrate and the Ni35WC coating, respectively. It is suggested that the improvement is closely related to the composite coating being strengthened owing to the increase of coating hardness, formation of a fine-grained microstructure caused by Co, and fine hard precipitate phases in the eutectic structure.

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