Effects of Composition on Antibacterial and Antiviral Properties of Suspension Plasma-Sprayed Hydroxyapatite/Titania Coating

2021 ◽  
Author(s):  
Mirazul Mahmud Abir ◽  
Yuichi Otsuka ◽  
Yukio Miyashita
Keyword(s):  
Raman Spectroscopy ◽  
Photocatalytic Activity ◽  
Oxygen Vacancies ◽  
Composite Coatings ◽  
Test Results ◽  
Good Efficiency ◽  
Femoral Stems ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Titania Coating

Abstract This study investigates the effect of composition on the antibacterial and antiviral properties of hydroxyapatite/titania composite coatings deposited by suspension plasma spraying. Hydroxyapatite is a bioceramic material used as a plasma-sprayed coating to promote osseointegration of femoral stems. TiO2 has promising photocatalytic activity and good efficiency in destroying bacteria, viral species, and parasites. Prior to coating, substrates were grit blasted, ultrasonically cleaned, and heated to enhance adhesion strength. The microstructure of the resulting coatings was then characterized using XRD and Raman spectroscopy. Test results indicated that SPS transformed Ti2O3 into TiO2 with mixed phases. Ti4O7 and Ti3O5 phases were also identified, which show photocatalytic activity due to oxygen vacancies. Antibacterial and antiviral tests were conducted as well.

Microstructural characteristics and protection performances of plasma-sprayed Al2O3–Al composite coatings on AZ91D magnesium alloy

2016 ◽  
Vol 23 (5) ◽  
pp. 467-474 ◽  
Author(s):  
Huanhuan Sun ◽  
Shuqin Ma
Keyword(s):  
Composite Coatings ◽  
Wear Test ◽  
Az91d Alloy ◽  
Test Results ◽  
Microstructural Characteristics ◽  
Az91d Magnesium Alloy ◽  
Eds Analysis ◽  
Al Composite ◽  
Chloride Environment ◽  
Plasma Sprayed

AbstractFour Al2O3-Al composite coatings were successfully fabricated on AZ91D alloy by plasma sprayed with changing ratios of Al2O3 and Al mixed powders, respectively. XRD results indicate that all the composite coatings are composed of γ-Al2O3, α-Al2O3, and Al. SEM and EDS analysis find that Al2O3-Al composite coatings present the interlaced structures of Al and Al2O3 bands. VIDAS image analysis reveals that the porosities of the composite coatings are increased by adding Al2O3. In the composite coatings, the hardness of Al is about 62 HV and that of Al2O3 is up to 1380 HV. The electrochemical polarization tests testify that Al2O3-Al composite coatings can effectively protect AZ91D alloy from corroding in a chloride environment. The wear test results confirm that the wear resistance of Al2O3-Al composite coatings is markedly superior to that of AZ91D alloy. The excellent protection degrees are attributed to their particular compositions, microstructures, and properties. Moreover, the effect of Al2O3 contents on the microstructures and protection performances of Al2O3-Al composite coatings was also studied and discussed in detail.

Improve Stability of Dicalcium Silicate/Zirconia Composite Coatings by Post-Spraying Heat Treatment

2005 ◽  
Vol 107 ◽  
pp. 141-144 ◽  
Author(s):  
Youtao Xie ◽  
Paul K. Chu ◽  
Xuan Yong Liu ◽  
Chuan Xian Ding
Keyword(s):  
Heat Treatment ◽  
Composite Coatings ◽  
Immersion Test ◽  
Dicalcium Silicate ◽  
Test Results ◽  
Long Term Stability ◽  
The Stability ◽  
Plasma Sprayed ◽  
Sprayed Coatings

The long-term stability of plasma-sprayed dicalcium silicate (C2S) composite coatings is determined by the phase composition, crystallinity, and other properties. Zirconia reinforcement and post-spraying heat treatment are applied to C2S coatings simultaneously in this work. The stability of the coating increases evidently by reinforcement with 70wt% zirconia and heat treatment at 800oC for 4 hours. SEM reveals that the smooth glassy surface of the as-sprayed coatings is replaced by randomly dispersed crystals. Tris-HCl immersion test results show that the dissolution rate of the composite coatings decreases after the heat treatment.

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.

STUDY ON THE MECHANISM OF VISIBLE ABSORPTION ENHANCEMENT FOR N+ IMPLANTED TiO2 BY RAMAN SPECTROSCOPY

2011 ◽  
Vol 18 (03n04) ◽  
pp. 135-140
Author(s):  
CHUN-XIAO WANG ◽  
YAN CHEN ◽  
YU-ZUN FAN ◽  
YAN-WEN ZHANG ◽  
QI-YU LIANG ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Photocatalytic Activity ◽  
Raman Spectra ◽  
Absorption Edge ◽  
Oxygen Vacancies ◽  
Visible Region ◽  
Absorption Enhancement ◽  
Visible Absorption

The photoabsorption edge shifting from UV to visible region accompanied with increased intensity and Raman features change was observed for N+ implanted TiO2 . Raman spectra prove the formation of TiN x and oxygen vacancies in the implanted TiO2 , which is considered as the origin of absorption edge shifting. The work may give a hint to increase the photocatalytic activity of TiO2 in the visible region at the molecule level.

scholarly journals Microstructural Charactistics of Plasma Sprayed NiCrBSi Coatings and Their Wear and Corrosion Behaviors

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 170
Author(s):  
Songqiang Huang ◽  
Jingzhong Zhou ◽  
Kuoteng Sun ◽  
Hailiang Yang ◽  
Weichen Cai ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Acid Corrosion ◽  
Composite Coatings ◽  
Atmospheric Plasma ◽  
Confocal Laser ◽  
Formation Mechanisms ◽  
Temperature Oxidation ◽  
Surface Protection ◽  
Plasma Sprayed ◽  
Nicrbsi Coatings

Nickel-based alloys are commonly used as protective coating materials for surface protection applications owing to their superior resistance to corrosion, wear and high-temperature oxidation. It is urgent to study the fundamental mechanism between the structure and corrosion properties of the Nickel-base composite coatings. This paper, therefore, focuses on clarifying the mechanisms of the microstructure influencing the acid corrosion and mechanical characteristics of the as-sprayed NiCrBSi coating and post-heat-treated coating. The formation mechanisms of the amorphous phase of flat particles during the plasma spray process were studied by using X-ray diffraction analysis, Raman spectroscopy and confocal laser scanning microscope at first. Then the evolutionary process of the corrosion structure and phase of the coating in the accelerated corrosion experiment is directly visualized by using scanning electron microscopy and energy spectrum analysis. The mechanical properties of the amorphous NiCrBSi coatings are lastly measured by microhardness and friction wear tests. The critical phenomena and results help to elucidate the relative influence of the surface features of atmospheric plasma sprayed coatings on acid corrosion responses and wear resistance, aiming at contributing to the development of a protective technique for electrical engineering.

Evaluation of Slurry Erosive Wear Performance of Plasma-Sprayed Flyash-TiO2 Composite Coatings

2021 ◽  
Vol 7 (3) ◽  
Author(s):  
R. Keshavamurthy ◽  
B. E. Naveena ◽  
C. S. Ramesh ◽  
M. R. Haseebuddin
Keyword(s):  
Composite Coatings ◽  
Erosive Wear ◽  
Wear Performance ◽  
Plasma Sprayed
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