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.

Dissolution Behavior of WC Reinforced Particles on Carbon Steel Surface during Laser Cladding Process

2012 ◽  
Vol 430-432 ◽  
pp. 137-141 ◽  
Author(s):  
Zhong Zhang ◽  
Hong Xi Liu ◽  
Xiao Wei Zhang ◽  
Sheng Wei Ji ◽  
Ye Hua Jiang
Keyword(s):  
Carbon Steel ◽  
Composite Coating ◽  
Laser Cladding ◽  
Laser Scanning ◽  
Energy Dispersive Spectrometer ◽  
Scanning Speed ◽  
Decomposition Reaction ◽  
Medium Carbon Steel ◽  
Dissolution Behavior ◽  
Laser Scanning Speed

Ni60WC35 self-fluxing composite coating was fabricated by transverse-flow CO2 laser apparatus on 45 medium-carbon steel surfaces. The microstructure and phase transform behavior of WC reinforced particles under the laser cladding conditions was investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy-dispersive spectrometer (EDS). The results show that laser scanning speed has a great important influence on the microstructure of Ni-based WC composite coating, WC particles has a transition to the Ni-based coating. The main feature of WC particle is its edge hard phase has transformed into needle phase, and the needle phase areas increase with the decrease of the laser scanning speed. Some WC particles turn into needle clusters structure, and then white block phase. In addition, WC particle has some microscopic defects, and the surface priority defect can be dissolved. When the pool temperature rises to 1250°C, WC decomposition reaction become W2C and C. The elements diffusion can promote the dissolution of WC particles when the pool temperature rises continuously.

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.

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.

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.

Effect of laser scanning speed on microstructure and wear properties of T15M cladding coating fabricated by laser cladding technology

2018 ◽  
Vol 110 ◽  
pp. 163-171 ◽  
Author(s):  
Xiangyi Jiao ◽  
Jun Wang ◽  
Canming Wang ◽  
Zhengqi Gong ◽  
Xinxing Pang ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Wear Properties ◽  
Laser Scanning Speed

scholarly journals The Effect of Laser Scanning Speed on Microstructure and Performance of Cr3C2-NiCr Cermet Fabricated by in-situ Laser Cladding

2021 ◽  
pp. X
Author(s):  
Deyuan LOU ◽  
Shaokun YANG ◽  
Sheng MEI ◽  
Qing LIU ◽  
Jian CHENG ◽  
...  
Keyword(s):  
Laser Cladding ◽  
Laser Scanning ◽  
Scanning Speed ◽  
Powder Mixtures ◽  
Laser Scanning Speed ◽  
Nickel Based Alloy ◽  
And Performance ◽  
Microstructure And Performance ◽  
Carbide Content

To explore the effect of laser scanning speed on the microstructure and performance of Cr3C2-NiCr cermet layers fabricated by in-situ laser cladding, Cr3C2-NiCr cermet layers were laser cladded from Ni/Cr/Graphite (25:65:10 wt.%) elemental powder mixtures. The microstructures of the laser cladded cermet layers and the formation mechanism were investigated. In addition, the effect of laser scanning speed on the microstructure, friction and corrosion performance of the Cr3C2-NiCr cermet layers was studied. The results indicated that the in-situ laser cladded Cr3C2-NiCr cermet layers were composed of NiCr binder and Cr3C2. The laser scanning speed had a significant influence on the carbide content, composition and size. Furthermore, it affected the in-situ laser cladded cermet layer’s hardness and wear resistance. The corrosion resistance of the in-situ laser cladded cermet layer was superior to that of laser cladded nickel-based alloy and was improved with decreasing laser scanning speed.

Microstructure of Laser In Situ Synthesized TiBx+TiC Reinforced Composite Coatings

2014 ◽  
Vol 1061-1062 ◽  
pp. 526-529
Author(s):  
Jing Liang ◽  
Chao Wang ◽  
Sui Yuan Chen ◽  
Chang Sheng Liu ◽  
Cheng Yu Yang
Keyword(s):  
Laser Scanning ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Processing Parameters ◽  
In Situ Synthesis ◽  
Optimal Processing ◽  
Reinforced Composite ◽  
The Matrix ◽  
Laser Scanning Speed

B4C/TiNi mixed powders with different composition (10B4C+90TiNi and 20B4C+80TiNi in wt. %) prepasted on Ti-6Al-4V substrates were scanned by a FL-Dlight02-3000W semiconductor laser to obtain TiBx+TiC reinforced graded composite coatings. The influences of the processing parameters on the microstructure of the coatings were studied. Optimal processing parameters were obtained with laser power (P) 1700W/1900W, laser scanning speed (V) 6.67mm/s and defocus length 310mm. The microstructures and phases of the coatings were analyzed with OM, SEM and XRD respectively. Graded composite coatings with in-situ synthesis of TiC, TiB and TiB2 reinforcements in the matrix of Ti2Ni and TiNi were obtained.

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