Papers by Keyword: Wear Resistant

Abstract: The composition of the electrolyte-colloid was optimized by the method of mathematical planning of extreme experiments of Box-Wilson to obtain a composite electrochemical coating of nickel-nanodiamond. Polarization researches have shown a decrease in polarization in electrolytes containing diamond nanoparticles. The effect of the colloidal phase introduced into the electrolyte or formed during the electrolysis process on the electroplating process and the quality of precipitation was discussed. The wear resistance, microhardness, corrosion resistance of these deposits was investigated. These semi-bright and wear-and corrosion-resistant (Corrodcote-test) coatings are recommended as a substitute for electroplated chromium (better ecology). The morphology and surface of electroplating nanoparticles based on nickel were investigated using the «semi-contact» method on a PHYWE atomic force microscope. The leveling effect of diamond nanoparticles is shown.

Abstract: This study develops a new, facile and rapid process bioinspired on rice leaf with the aim of producing a hybrid composite coating in a first attempt to obtain a superhydrophobic coating with enhanced erosion resistance properties. Rice leaves (Oryza sativa L.) are made of hierarchical structures consisting of micropapillae and waxy nanobumps which confer to the surface a contact angle of 164° as Lotus leaf does. In particular, rice leaves accumulate amorphous silica inside and on the surface with various morphologies. This kind of silica is produced by absorbing silicates from the soil under specific conditions of temperature and pressure. The presence of biosilica in rice leaves is useful for preventing diseases or improves mechanical properties of the leaves. Single-step and two-step processes are the two strategies applied for generating a superhydrophobic coating by electrochemical deposition of ZnCl₂, α-Al₂O₃ and lauric acid (C₁₁H₂₃COOH) onto commercial pure aluminum substrate. The static contact angle measured on the coating gives values of 170° and 1° for the sliding angle conducing to a coating with superhydrophobic and self-cleaning properties. Various characterization techniques are used to determine chemical and morphological structure such as FESEM, XPS or FTIR. On one hand, in morphological analysis, flower-like structure is obtained with petals thickness of 70nm corresponding to the nanostructured contribution to the system. On the other hand, chemical analysis concludes the generation of zinc laurate (Zn (C₁₁H₂₃COO)₂) as a major compound contributing to the reduction of surface tension and increasing the superhydrophobic character of the coating as well.

Abstract: This paper presents the applications of advanced CVD Tungsten Carbide coating to extend the life of tooling used for forming abrasive and corrosive materials.Hardide nanostructured Tungsten Carbide coating combines high hardness (70-77Rc) with excellent toughness. Unlike other hard coatings Hardide can produce a conformal coating layer on complex-shaped tools, including internal surfaces of extrusion die cavities and moulds. In ASTM G65 test the Hardide coating abrasion resistance exceeded WC/Co (9%) cemented carbide by a factor of 4X, and D2 tool steel by 10X. Thus the coating can significantly increase the life of D2 steel tooling used for forming abrasive materials and by maintaining better dimensional tolerances and surface finish of the tool it will manufacture better quality products.The Hardide coating has enhanced resistance to corrosion and aggressive media, including acids; this makes the coating especially suitable for the tooling used in forming uPVC, PTFE and other corrosive materials.The Hardide coating has been tested on extrusion and pelletizing dies processing abrasive and corrosive slurries and typically showed a 3X increase in the life of the tooling. Similar results were achieved by the coating of powder compaction punch/die sets for pharmaceuticals tableting.

Abstract: Detonation gun spray coating method (D-Spray) is an effective method of coating process [4]. The surface property of material will be enhanced by deposition of coating powders such as metal oxides and ceramics like aluminium oxides, tungsten carbide, nickel chromium etc. which improves micro hardness, corrosion and wear resistant resistance property. This coating process is applicable in different engineering sectors such as aviation industry, marine industry, biomedical industry etc., In this Experimental study the Process parameter optimization of D-spray coating process with different coating powder was done by Taguchi design of experiment [2] and interrelationships among multiple response was analysed with Grey relation Analysis [2] in order to find the optimized processing conditions and to get higher quality of coating. Micro hardness Wear resistant, Surface roughness are the multiple responses estimated for various combinations of parameters and the optimum process parameters were obtained.

Abstract: The objective of this study was to develop clad layer by producing a Silicon Carbide (SiC) particle reinforced Metal Matrix Composite (MMC) using the iron based alloys (P25) as the matrix material. Direct laser cladding was carried out by melting the clad materials and depositing them onto a mild steel substrate. A two gravity feed system was used in this study which contained of SiC particles and iron based powder as separate powders. The intention was to melt the iron based powder and incorporate the SiC particles. Decomposition of SiC particles was observed and only a few SiC particles were found in the clad matrix. Microhardness results showed that laser clad layer had higher hardness which more than 1000 HV and hence potentially better wear resistance that base material. However, most of the SiC had evaporated which created porosity in the melt pool due to the decomposition of SiC and the resultant gas which was trapped in clad layer did not have enough time to escape from the melt pool due to the rapid solidification. Therefore, a blown powder technique is recommended for overcome this problem.

Abstract: The objective of this research was to develop a new form of clad layer by producing a Silicon Carbide (SiC) particle reinforce Metal Matrix Composite (MMC) using the iron based alloys as the matrix material. A 1.2kW continuous wave CO₂ laser was used in this research. A gravity feed system was used with one powder feed which contained different percentages of SiC particles and iron based powder. Experimental results showed that the decomposition of SiC particles was observed and only a few SiC particles were found in the clad matrix. High micro hardness values were found in the SiC clad which were in excess of 1000 HV. However, most of the SiC were evaporated which created porosity in the melt pool. Therefore, blown powder technique is recommended for overcome this problem.

Abstract: The key in restricting CFB (circulating fluidized bed) boiler running was material selection, construction fixing, pouring, coating, structure designing and running mode of wear resistant and refractory nonmetal material. Based on the comparison of CFB boiler and PC boiler, this paper expatiated on the failure, abrasion mechanism, material capability and selecting material principle of wear resistant and refractory nonmetal material, pointed out mistakes of utility boilers material selection and arranged reasonable principle of selecting material from the angle of improving working life of boiler and enhancing wearing resistance property of boiler.

Abstract: Base on the blending modification and the toughness reinforcing method,choosing the thermoplastic poly-ether-polyurethane as the glue stocks of the inner layer, reinforcing the intension of the fiber layer,using the thermoplastic polyurethane and EPDM blending test，imprvoing the production technology of the inner layer and the outer layer,making imprvoing for the wear-resistant of layflat polyurethane hose.

Abstract: Spraying wire was widely used in remanufacturing work piece for worn failure. With the demand of high abrasion resistant wire, new type alloy was developed. The solidification structures of the new high abrasion resistant alloy (HARA) containing Mn, Cr, Si, C and the structure was studied after tension by scanning electron microscopy (SEM). The phase evolution was analyzed by X-ray diffraction and Rockwell hardness evaluated on the hardness testing. The abrasion behavior of HARA alloy used in the liner of wet-grinding machine in metallurgical industry is investigated under impacted energy of 0.5-3 J in acid-ironstone slurry; the test was carried out by a modified MLD-10 tester. The result show that the solidification structures of HARA alloy consist of austenitic Fe and the hardness neared to HRC60. Under the high energy, the wear resistance of HARA alloy is three times more than Mn13. Therefore, the new material has better abrasive wear resistance and lower environmental impact

Abstract: Flame sprayed iron tailings coatings on the boiler steels are characterized before and after melting. The attempt has been made to investigate the microstructure, erosion resistant, wear resistant of the coated and melted samples. The techniques used are SEM and XRD. The results show that: Good adhesion between the coating and the substrate is caused by the formation of Al₂SiO3 and (Cr, Fe)₂O₃ at the interface of the coated specimen. The stainless steel substrate with ceramic coating has a higher erosi_{Subscript text}on resistance than the uncoated specimen because the mixed powder changes to a glass-coating in the high temperature heat treatment, and a few mullite are formed. Mullite has the high hardness value that makes the hardness of the coating increased. The wear resistance of the coated samples is better than that of the uncoated samples because glass-coating is more smooth than the uncoated specimen and the mullite in the coating has the high hardness value that makes the hardness of the coating increased.