Titanium Plasma-Sprayed Coatings on Polymers for Hard Tissue Applications

The paper presents the results of titanium plasma spraying (TPS) on polymer substrates. Polyethylene (PE300), polyamide PA6, and fiber glass-reinforced polyamide (PA6.6-GF30) were used as substrates. The PE300 and PA6.6-GF30 substrates exhibited appropriate behavior during the TPS process, whereas the PA6 substrate did not “accept” Ti during plasma spraying, and the coating did not form. The TPS coatings exhibited low porosity and high homogeneity, and they had a typical multilayer structure composed of Ti and its oxides. The nanoindentation test showed good mechanical properties of the coatings and demonstrated a hardness and a Young’s modulus of approximately 400 HV and 200 GPa, respectively. The bending test confirmed the good adhesion of the titanium coatings to the polymer substrates. The Ti coatings did not fall off the substrate after its significant bending deformation.

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Study of the Adhesion Strength of Plasma-Sprayed Coatings Using Statistical Methods

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.897.56 ◽

2020 ◽

Vol 897 ◽

pp. 56-60

Author(s):

Nikolay Kuleshov ◽

Nikolay Dolgov ◽

Igor Smirnov ◽

Leonid Vinogradov ◽

Vladimir Shestakov

Keyword(s):

Plasma Spraying ◽

Adhesion Strength ◽

Ceramic Coatings ◽

Optimization Criterion ◽

Alumina Powder ◽

Nano Powder ◽

Plasma Sprayed Coatings ◽

Tensile Adhesion ◽

Plasma Sprayed ◽

Sprayed Coatings

The adhesion strength of plasma-sprayed ceramic coatings was studied. Alumina powder was used for plasma spraying. A titanium oxide Nano powder with a particle size of 40-50 [nm] was used as a modifier. The optimal conditions of plasma spraying of coatings are established. The adhesion strength was used as an optimization criterion. Coating adhesion was determined by tensile adhesion testing. A mathematical model is obtained that allows one to determine the effect of spraying conditions (lens current, arc current, and the position of the solenoid relative to the nozzle) on the adhesion strength.

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Self-Lubricating Composite Plasma Sprayed Coatings

Thermal Spray 1996: Proceedings from the National Thermal Spray Conference ◽

10.31399/asm.cp.itsc1996p0355 ◽

1996 ◽

Author(s):

D. Niebuhr ◽

M. Scholl ◽

P. Clayton

Keyword(s):

Plasma Spraying ◽

Solid Lubricants ◽

High Energy ◽

Contact Conditions ◽

Steel Coating ◽

Contact Loads ◽

Soft Metal ◽

Plasma Sprayed Coatings ◽

Plasma Sprayed ◽

Sprayed Coatings

Abstract Composite self-lubricating coatings were developed using high-energy plasma spraying (HEPS). These coatings would be potentially used in high contact pressure rolling/sliding systems. The coatings are based on a steel coating deposited by high energy plasma spraying using wire feedstock. Solid lubricants such as graphite and soft metal were investigated. Twin roller rolling/sliding tests were performed at 5% and 35% creep and contact loads of 700 N to 1700 N on a 5 mm contact face. Reduced friction, compared to a steel coating-steel or 1080 wrought steel couple was observed under these rolling-sliding contact conditions.

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Novel Zro2-Mullite Composites Produced by Plasma Spraying

Thermal Spray 1998: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc1998p1233 ◽

1998 ◽

Author(s):

K.A. Khor ◽

Y. Li

Keyword(s):

Plasma Spraying ◽

Structural Integrity ◽

Plasma Jet ◽

Distilled Water ◽

Composite Powders ◽

Plasma Flame ◽

Amorphous Phases ◽

Plasma Sprayed Coatings ◽

Plasma Sprayed ◽

Sprayed Coatings

Abstract Zirconia can induce enhanced fracture toughness to a number of ceramics when introduced as a reinforcement either in the form of particulates, dispersed phase or whiskers because of its unique tetragonal-monoclinic (t-*m) transformation. This paper presents the preparation of Zr0 2 reinforced mullite by plasma spraying a mixtures of zircon and alumina. The dissociation of zircon into zirconia and silica in a plasma flame is well-known. Pre-mixed powders of zircon and alumina are injected into a dc plasma jet. The plasma sprayed particles are collected in distilled water and analyzed. The results indicate that the plasma sprayed powders consist of zirconia, zircon and alumina. It was found that fine, mostly amorphous and chemically homogeneous composite powders can be obtained by ball milling and plasma spraying. Recrystallization of amorphous phases and formation of mullite occurred at about 1000 °C in plasma sprayed powders. This value is more than 500 °C lower than the formation of mullite in as-milled powders. Uniform coatings with good structural integrity were obtained by plasma spraying. The amount of amorphous phases was much higher in plasma sprayed coatings than in spheroidized powders, and the relative quantity of mullite in coatings after heat treatment is about 4 times as much as that obtained in the spheroidized powders.

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Comparison of Plasma-Sprayed Coatings Produced in Argon or Nitrogen Atmosphere

Thermal Spray 1997: Proceedings from the United Thermal Spray Conference ◽

10.31399/asm.cp.itsc1997p0459 ◽

1997 ◽

Author(s):

M. Leylavergne ◽

A. Vardelle ◽

B. Dussoubs ◽

N. Goubot

Keyword(s):

Plasma Spraying ◽

Nitrogen Atmosphere ◽

Cryogenic Cooling ◽

Ambient Atmosphere ◽

Air Plasma ◽

Spray Process ◽

Plasma Sprayed Coatings ◽

Plasma Sprayed ◽

Thick Coatings ◽

Sprayed Coatings

Abstract When spraying is conducted in the ambient atmosphere, the entrainment of air cools down the plasma jet and affects its expansion. It may also cause the oxidation or the chemical decomposition of the sprayed materials. Inert Plasma Spraying (IPS), generally conducted in argon atmospheres, prevents these phenomena. However, the main drawbacks of IPS in comparison with air plasma spraying are the capital and apparating costs. To reduce the latter by 25 to 30%, nitrogen atmospheres may be used as a substitute for the conventional argon atmosphere. This paper presents a study in which titanium carbide and niobium powders were sprayed in argon and nitrogen atmospheres. Cryogenic cooling of the substrate was used during the spray process. This helps to maintain a low temperature in the chamber, produces thick coatings and allows the use of substrate materials that are sensitive to heat. The adhesion, roughness and microstructure of the coatings produced in both atmospheres are compared as well as their nitrogen content.

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