Papers by Keyword: Powder Coating

Abstract: The results of a technological process development for obtaining a wear-resistant powder coating of Ni-Mo-Al system, applied by cold gas-flame spraying to the surface of a critical unit of compressor equipment in the oil and gas industry, within the framework of repair production are presented. Using scanning electron microscopy (SEM), the features of the structure and distribution of alloying elements in the coating are determined. The authors rationalized mechanical processing of the surface layer in order to obtain minimum roughness of the working area of the compressor cylinder. It is shown that the sprayed coating of Ni-Mo-Al system has a satisfactory adhesion strength in the range of 30-50 MPa, microhardness of 200-210 HV, which provides an increased running-in rate of piston rings of 6-10 mm³/Nm when operating the compressor in the temperature range of 350 - 400 °C. The parameters of finishing machining process of the finished coating are worked out, which makes it possible to ensure the minimum possible roughness of the coating of Ni-Mo-Al system in the range of 0.08-0.15 Ra in order to reduce wear of the working surface and extend service life.

Abstract: There are shown studies on influence of film-forming components on the corrosion resistance of powder coating. Protective and decorative powder coatings - one of the most promising types of paints and varnishes for industrial use. Their main advantages are: absence of solvents, practically waste-free coating technology (the degree of powder utilization during application is close to 100 relative simplicity and cost-effectiveness of the production process of coating. The study of protective properties of powder coatings is associated with the detection of high performance properties and high corrosion resistance of the material. Although corrosion resistance of powder coating performance continues to improve via the design of more effective film-forming components the nomenclature of which is wide enough.

Abstract: Mineral fertilisers such as nitrous, phosphorous and potassium (NPK –usually called macro elements) are one of the most significant products in agricultural industry. By providing nutrients to the plants, they play an important role in the process of regulating the acidity (pH) and the fertility of the soil and all it leads to increase the crops growth [6].

Abstract: The appropriate use and in adequate quantities of synthetic slags in continuous casting process (insulating coating powder in tundish and respectively lubricant molding powder in crystallizer) gives a good quality of continuous castings products. The paper presents two methods of determining the necessary of slags: using dispersion analysis software Minitab.v17 and optimization of heat transfer in tundish, depending on powder coating thickness, performed with a program made in Mathcad14 and respectively optimization of the molding powder thickness, using an own simulation program. Both methods are based on the properties of steel grade which is casted (in particular the liquidus temperature of the steel) and they can be adapted to the specifics of the continuous steel casting machines.

Abstract: Key stages for providing functional properties to polymeric coatings based on powder paints in order to reduce the rate of electromagnetic radiation due to treatment in planetary ball mill were studied. While varying the time of the treatment, as well as the filler weight fraction, the properties of powder mixtures, as well as the structure and properties of the coatings were investigated. Functionality of the coatings was achieved through adding shielding filler (the powder of Cr17Ni2steel) into powder paint and their subsequent treatment in a planetary ball mill.

Abstract: For operating under outer space conditions besides providing originally specified protective function, coating should often ensure accomplishment of functional properties, for instance conductivity of electric current. The solution of this problem can be reached by adding powder fillers with specified functional properties into powder paint. The paper deals with development of technique for formation of protective conducting coatings by filling powder paints and treatment in planetary ball mill. For protection of magnesium alloy shells the technique is offered which combines formation of the oxidized sublayer, introduction of electroconductive filler, treatment of the powder mixture in the planetary ball mill and electrostatic deposition of sifted mixture of definite dispersion. This allows sinking of static electricity from cabinets of the equipment for the space-crafts applications in conditions of the outer space.

Abstract: The aim of the current study was to elaborate and compare abrasive wear resistance of thick metal matrix based deposited coatings. To produce metal matrix composite (MMC) coatings, experimental powders made by mixing commercial nickel and iron based powders with recycled hardmetal powder were used. The usage of recycled hardmetal as an initial material can significantly decrease the cost of production, improve the mechanical characteristics of coatings and consequently increase their wear resistance. Based on structural studies the optimal content of 40 vol% hard phase was selected. Plasma transferred arc (PTA) hardfacing and high velocity oxyfuel (HVOF) spraying were used as deposition technologies. The behavior of coatings by abrasive rubber wheel wear (ARWW ) (based on G 65 standard), abrasive impact wear (AIW) and abrasive erosion wear (AEW) (based on GOST standard) was investigated. The results showed that the wear resistance of experimental PTA hardfacings at high angle impact wear conditions is notably higher than of HVOF sprayed coatings.

Abstract: In current article, applications of pulsed electromagnetic fields (PEMF) for processing of powder parts obtaining bronze coating on a steel rod are presented. Experiments were carried out in Laboratory of Metal Forming Technology (University of Applied Sciences of Zwickau, Germany) and in Laboratory of Powder Materials (Riga Technical University, Latvia). An adhesion strength between steel and bronze parts was measured by means of a shearing test.

Abstract: The deposition of copper onto acrylic resin powder in its self-convective motion by magnetron DC sputtering was examined in order to prepare granular polymeric spacers coated with the metal, aiming at enhancing the cell wall structure of sintered highly porous aluminum materials. The fabrication of sintered highly porous aluminum materials was carried out in an ordinary powder metallurgy processing combined with a space-holder method with the polymer-copper binary spacer granules prepared by powder-coating using the sputter-deposition technique. The effects of the sputter-deposition of copper onto the spherical polymeric spacers on cell structures of the sintered porous compacts were investigated. According to optical observations, it was found that the sputtered copper could be uniformly and adherently deposited onto the surface of the acrylic granules. According to EPMA analysis on the cross-section on a sintered porous compact, it was found that Cu atoms were distributed at the vicinity of its cell walls, concluding that cell wall structures could be enhanced by this processing. Therefore it was expected that the compressive properties of the sintered highly porous aluminum materials were also improved by this powder coating process.

Abstract: Metals, despite their deterioration in a corrosive atmosphere, continue to dominate the automotive, agricultural, furniture, process and appliance industries and HRS (Hot Rolled Steel) plays a significant role in those areas. Powder coating on HRS is widely employed for protective and aesthetic purposes. Prior to powder coating, phosphating conversion coating is often used to increase effectiveness of protection. However, due to tightening environmental legislations, phosphating process is now problems for industry. Therefore, newly developed environmentally friendly conversion coats are introduced to industry. In this study a new environmentally friendly zirconium fluoro-based (H2ZrF6) generation of conversion coating has been introduced to replace the conventional phosphating conversion coatings process. It is deposited on the surface with a thin nanometre range, therefore shortening the process, which also has advantages such as being free of heavy metal and operating in low or ambient temperature. The present work closely examines Zr based nano structured conversion coatings for HRS. Extensive corrosion and adhesion studies are carried out on differently prepared HRS test panels, pre-treated with Zr based conversion coating in various conditions, such as different composition ratio, temperature and contact time.