Microstructure and Bonding Feature of the Bioceramic Composite Coating Obtained by Nd: YAG Laser Cladding

2007 ◽  
Vol 361-363 ◽  
pp. 697-700
Author(s):  
Ying Chun Wang ◽  
Yan Min Li ◽  
Zhen Min Xu ◽  
Qi Lin Deng ◽  
Jian Guo Li ◽  
...  
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
316L Stainless Steel ◽  
Ceramic Coatings ◽  
Metal Substrate ◽  
Composition Gradient ◽  
X Ray Diffraction ◽  
Calcium Phosphate Ceramic ◽  
X Ray ◽  
Metallurgical Bonding

Undesirable phase and microstructure formation, and poor HAP/metal bonding strength restrict the fabrication technique to obtain HAP and other calcium phosphate ceramic coatings. In this paper a bioceramic composite coating, which includes HAP andβ-Ca2P2O7, was obtained by laser cladding with pre-depositing mixed powders of CaHPO4·2H2O and CaCO3 directly on the 316L stainless steel metal substrate. The phases, microstructure and bonding feature of the bioceramic composite coating are characterized by X-ray diffraction(XRD), scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS). The microstructure of the coating consists of minute granular HAP that is distributed among the overlapped club-shapedβ-Ca2P2O7. Uniform presences of Ca, P and O in bioceramic composite coating supplie necessary elements for the synthesis of HAP andβ-Ca2P2O7. Diffusions inwards of P and O into alloying layer help form the chemical metallurgical bonding and composition gradient distributions are present. a chemical metallurgical bonding was formed between the bioceramic composite coating and metal substrate.

Effect of oxidation time on the microstructure and properties of ceramic coatings prepared by microarc oxidation on 7A04 superhard aluminum alloy

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744026
Author(s):  
Feng Xiao ◽  
Hui Chen ◽  
Jingguo Miao ◽  
Juan Du
Keyword(s):  
Aluminum Alloy ◽  
Microarc Oxidation ◽  
Ceramic Coatings ◽  
Ceramic Layer ◽  
X Ray Diffraction ◽  
Oxidation Treatment ◽  
X Ray ◽  
Metallurgical Bonding ◽  
Dense Ceramic ◽  
Morphology Of Surface

Under the sodium aluminates’ system, microarc oxidation treatment was conducted on the superhard aluminum alloy 7A04 for different times. The microstructure of microarc oxidation ceramic layer was investigated by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). The influences of different oxidation times on the adhesion strength of ceramic layer and substrate, the morphology of surface and cross-section, the phase composition and the electrochemical properties were studied. The results indicated that the connection of the coating and substrate appears to be metallurgical bonding and dense ceramic layer, and the surface is in a “volcanic vent” morphology, which is composed of [Formula: see text]-Al2O3 and little [Formula: see text]-Al2O3. The corrosion resistance of ceramic layer is improved significantly in contrast with that of the substrate.

scholarly journals Effect of Rare Earth Oxides on Microstructure and Corrosion Behavior of Laser-Cladding Coating on 316L Stainless Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 636 ◽  
Author(s):  
Xu ◽  
Wang ◽  
Chen ◽  
Qiao ◽  
Zhang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Rare Earth ◽  
Corrosion Behavior ◽  
Laser Cladding ◽  
316L Stainless Steel ◽  
Electrochemical Impedance ◽  
Salt Spray ◽  
Rare Earth Oxides ◽  
X Ray Diffraction ◽  
X Ray

The effect of rare earth oxides on the microstructure and corrosion behavior of laser-cladding coating on 316L stainless steel was investigated using hardness measurements, a polarization curve, electrochemical impedance spectroscopy (EIS), a salt spray test, X-ray diffraction, optical microscopy, and scanning electron microscopy (SEM). The results showed that the modification of rare earth oxides on the laser-cladding layer caused minor changes to its composition but refined the grains, leading to an increase in hardness. Electrochemical and salt spray studies indicated that the corrosion resistance of the 316L stainless steel could be improved by laser cladding, especially when rare earth oxides (i.e., CeO2 and La2O3) were added as a modifier.

MICROSTRUCTURE AND WEAR RESISTANCE OF IN-SITU SYNTHESIZED TiB2–TiC/Fe COMPOSITE COATING BY LASER CLADDING

2020 ◽  
pp. 2050046
Author(s):  
TIANWEI YANG ◽  
ZHAOHUI WANG ◽  
SHIHAI TAN ◽  
FU GUO
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Material Surfaces ◽  
Metallurgical Bonding ◽  
Steel Surfaces

To increase the strength and wear resistance of material surfaces, various combinations of B4C and 80TiFe powder were mixed into a Fe60 self-fluxing alloy powder; the composite coatings reinforced by TiB2–TiC were successfully prepared on Q235 steel surfaces by laser cladding. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were used to study the microstructure and chemical and phase composition. Microhardness and wear testers were used to investigate the mechanical properties. The results show that the interfaces of composite coatings and substrate materials are excellent for metallurgical bonding. The block-like TiB2 particles and flower-like TiC particles are uniformly distributed in the cladding coating. When the mass fraction of the mixed powder is 30%, the average microhardness of the coating is approximately 1100 HV[Formula: see text], which is 50% higher than that without the mixed powder, and demonstrates the best wear with a performance twice as better as that of the substrate.

Study of Fe-Ni(Cr) Alloy and Nano-Al2O3 Particles Composite Coating Prepared by Laser Cladding

2006 ◽  
Vol 118 ◽  
pp. 585-590 ◽  
Author(s):  
Yeo Jian Hua ◽  
Zhang Wei ◽  
Gao Ming Xia ◽  
Zhang Qun Li
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Mechanical Characteristics ◽  
Dendritic Structure ◽  
Processing System ◽  
Wear Property ◽  
Chromium Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Iron Nickel

The experiments of laser cladding Ni-coated nano-Al2O3 powder were made on 2Cr13 stainless steel using 7kW CO2 laser processing system. The microstructure and mechanical characteristics of composite coating were tested by scanning electronic microscope (SEM), X-ray diffraction (XRD), energy dispersion analyzer of X-ray (EDAX) and microhardness tester. The results showed that the composite coating was composed of superfine cellular dendritic structure. The X-ray diffraction data revealed that the cellular grains were composed of nano-Al2O3 particles, iron nickel alloy and iron chromium alloy. The mechanical characteristics of composite coating greatly increased. Compared with parent metal, the average hardness of composite coating increased by 1 time, and its wear property increased by 1.25 times.

Study on WC-Ni60 Complex Coating by High Frequency Induction Cladding

2011 ◽  
Vol 675-677 ◽  
pp. 1299-1302 ◽  
Author(s):  
Xin Wei ◽  
Gui Qin Wang ◽  
Yong Feng Chang ◽  
Chao Liu
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
High Frequency ◽  
Electron Probe ◽  
Bonding Layer ◽  
Alloy Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallurgical Bonding ◽  
High Frequency Induction

In this paper, WC-Ni60 alloy composite coating with different contents of WC particles was prepared on the 45steel substrate by high frequency induction cladding. The Composition and microstructure were characterized by X-ray diffraction (XRD) and electron probe X-ray microanalysis (EPMA), the abradability and hardness were tested by UMT-2 tribometer and HV-50A durometer, respectively. The results showed that the hardness and wear resistance of coating were enhanced with the increasing of WC content. WC-Ni60 coating obtained the best wear resistance with the content of 50% WC. The hardness of the coating got the highest when the content of WC was 60%, but wear resistance decreased. The WC-Ni60 coating was reinforced for various hard phases and the metallurgical bonding layer about 10μm was formed between coating and 45steel substrate.

scholarly journals Investigation on Nano-Self-Lubricant Coating Synthesized by Laser Cladding and Ion Sulfurization

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Meiyan Li ◽  
Bin Han ◽  
Conghua Qi ◽  
Yong Wang ◽  
Lixin Song
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
Dendritic Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Atomic Force ◽  
Valence States ◽  
Microstructure Morphology ◽  
Better Than

The composite processing between laser cladding and low temperature (300°C) ion sulfurization was applied to prepare wear resistant and self-lubricating coating. The microstructure, morphology, phase composition, valence states, and wear resistance of the composite coating were investigated by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscope (XPS), and friction and wear apparatus. The results indicate that the laser cladding Ni-based coatings and the maximum hardness of 46.5 HRC were obtained when the percent of pure W powder was 10%, composed of columnar dendrites crystals and ultrafine dendritic structure. After ion sulfurization at 300°C for 4 h, the loose and porous composite coating is formed with nanograins and the granularity of all grains is less than 100 nm, which consists ofγ-(Fe, Ni), M23C6carbides, FeS, FeS2, and WS2. Furthermore, the wear resistance of the composite coating is better than the laser cladding Ni55 + 10%W coating, and the friction coefficient and mass losses under the conditions of dry and oil lubrication are lower than those of laser cladding Ni55 + 10%W coating.

Corrosion Resistance of Al2O3-ZrO2 Composite Coating by Microarc Oxidation on 2A12 Aluminum Alloy

2011 ◽  
Vol 189-193 ◽  
pp. 672-675
Author(s):  
Yu Hai Li ◽  
Yan Zhao ◽  
Bao Yi Li
Keyword(s):  
Aluminum Alloy ◽  
Composite Coating ◽  
Composite Coatings ◽  
Microarc Oxidation ◽  
Composite Ceramic ◽  
Ceramic Coatings ◽  
X Ray Diffraction ◽  
Mixed Electrolyte ◽  
X Ray ◽  
Thickness Meter

The Al2O3-ZrO2 composite ceramic coatings were prepared on 2A12 aluminum alloy by Microarc oxidation in the mixed electrolyte of 40g/L Na2SiO3 and 8g/L Na2WO4 solution containing different ZrO2 content particles. The thickness of the coatings was measured by an eddy current thickness meter. Microstructure and phase composition were analyzed by scanning election microscopy (SEM) and X-Ray diffraction (XRD), respectively. The experimental results show that ZrO2 in electrolyte can promote coatings growth; Al2O3-ZrO2 composite ceramic coatings consist of α-Al2O3, t-ZrO2, m-ZrO2, and ZrO2 is located in island-like discharge channels and does not destroy the integrity of composite coatings; There is scarcely any erosion on the surface of Al2O3-ZrO2 composite coatings because the intermediate product Zr(OH)4 could suppress composite coating corrosion.

PHASE CONSTITUENTS AND MICROSTRUCTURE OF Ti3Al/Fe3Al + TiN/TiB2 COMPOSITE COATING ON TITANIUM ALLOY

2011 ◽  
Vol 18 (03n04) ◽  
pp. 103-108 ◽  
Author(s):  
JIANING LI ◽  
CHUANZHONG CHEN ◽  
CUIFANG ZHANG
Keyword(s):  
Wear Resistance ◽  
Titanium Alloy ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Composite Coating ◽  
Laser Cladding ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Cladding Process ◽  
Scanning Electron

Laser cladding of the Fe3Al + B4C/TiN + Al2O3 pre-placed powders on the Ti-6Al-4V alloy can form the Ti3Al/Fe3Al + TiN/TiB2 composite coating, which improved the wear resistance of the Ti-6Al-4V alloy surface. In this study, the Ti3Al/Fe3Al + TiN/TiB2 composite coating has been researched by means of X-ray diffraction and scanning electron microscope. It was found that during the laser cladding process, Al2O3 can react with TiB2 , leading to the formations of Ti3Al and B . This principle can be used to improve the Fe3Al + B4C/TiN laser-cladded coating on the Ti-6Al-4V alloy. Furthermore, during the cladding process, C consumed the oxygen in Fe3Al + B4C /TiN + Al2O3 molten pool, which retarded the productions of the redundant metal oxides.

Fabrication of Bioactive HA/Ti Composite Coating by Laser Cladding

2007 ◽  
Vol 330-332 ◽  
pp. 569-572 ◽  
Author(s):  
Sen Yang ◽  
Hau Chung Man
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Biomedical Applications ◽  
Bone Growth ◽  
Niti Alloy ◽  
Experimental Result ◽  
Chemical Compositions ◽  
X Ray ◽  
Metallurgical Bonding

To accelerate the bone growth around a metallic implant and to achieve the mechanical characteristics needed for biomedical applications, a HA/Ti composite coating was produced on NiTi alloy substrate by laser cladding. The chemical compositions, microstructures and surface morphology of the cladded layer were analyzed using energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and X-ray diffractometry (XRD). The experimental results showed that an excellent metallurgical bonding between the coating and the substrate was obtained. Owing to decomposition of HA under irradiation of high power laser, the microstructures in bioceramics coating were mainly composed of CaO, CaTiO3, Ti4P3, and HA phases. In vitro experimental result showed that HA/Ti composite coating made the bioactivity of NiTi alloy improve remarkably, which would promote the bone growth and could restrain Ni ion releasing from NiTi alloy.

Amorphization of Fe-Ni Based Alloys by Laser Cladding and Remelting

2010 ◽  
Vol 97-101 ◽  
pp. 1420-1424 ◽  
Author(s):  
Pei Lei Zhang ◽  
Zhu Guo Li ◽  
Chen Wu Yao ◽  
Shun Yao ◽  
Feng Gui Lu
Keyword(s):  
Composite Coating ◽  
Amorphous Phase ◽  
Laser Cladding ◽  
High Power ◽  
Vickers Hardness ◽  
Raw Materials ◽  
Critical Factor ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
X Ray

The Fe32Ni32Si16B18Nb2, Fe31Ni31Si18B18Nb2 and Fe30Ni30Si20B18Nb2, (at. %) alloys are synthesized using low purity of raw materials by high power CO2 laser cladding with synchronous powder feeding. X-ray diffraction results show that the coating has an amorphous structure with some crystalline phases on it. The microstructure of the coatings changes with different amounts of Si. It can be observed that black nanocrystalline grains embedded in the amorphous phase in the TEM image. The coating of Fe31Ni31Si18B18Nb2 alloy was annealed at different temperature for 30 minutes and the microstructure were investigated. The highest Vickers Hardness had exceeded 1300 in the coatings. The amount of Si is a critical factor for fabricating a Fe-Ni based amorphous composite coating.

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