Wyniki wyszukiwania - BazTech

1

Fabrication and Compressive Properties of Open-Cell Ni-Mo-Cr (Hastelloy) Foams Manufactured by Electrostatic Powder Spraying

Kang Tae-Hoon, Kim Kyu-Sik, Lee Min-Jeong, Yun Jung-Yeul, Lee Kee-Ahn

Archives of Metallurgy and Materials

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2020

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Vol. 65, iss. 3

1081--1086

EN

An open-cell Ni-Mo-Cr foam was newly manufactured using electrostatic powder spraying process and its room-temperature compressive properties were investigated in this study. For manufacturing Ni-Mo-Cr foam, Ni-Mo-Cr powders were sprayed on the polyurethane pre-form by electrostatic powder spraying process. And then, Ni-Mo-Cr powder sprayed pre-forms were sintered at 1200°C, 1250°C, and 1300°C, respectively. The relative densities of Ni-Mo-Cr foams were measured at 4 ~ 5%. Room tempera-ture compressive curves of ESP Ni-Mo-Cr foams represented the typical compressive 3-stages (elastic, plateau, densification) of open-cell metallic foam. As a result of observation of deformed specimen, the fracture mode found to be changed from brittle to ductile as sintering temperature increased. Based on these findings, correlations between structural characteristics, microstructure, and compressive deformation behavior were also discussed.

2

Influence of repainting on the mechanical properties, surface topography and microstructure of polyester powder coatings

Szala M., Kot E. A.

Advances in Science and Technology. Research Journal

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2017

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Vol. 11, no 2

159--165

EN

The literature does not provide a systematic analysis of the effect of electrostatic powder coating repainting of structural and constructional aluminum elements on their technological parameters. It is industrial practice that worn or damaged coatings be repainted. It is crucial to determine the effect of electrostatic sprayed coatings repainting on their microstructure, roughness and mechanical properties. The aim of the work is to determinate the influence of repainting of powder deposited polyester coatings on their mechanical properties, roughness and microstructure. This study examined three different electrostatic spray epoxy coatings with matt, silk gloss and fine structure-matt finish. Test panels were prepared as single- and double-layer paint coatings on the aluminum alloy 6060 substrate. Hence, six test sets of coatings were deposited. Each set contained six samples. The microstructure of the cross section of coating was investigated by scanning electron microscopy (SEM) and light optical microscopy (metallographic and stereoscopy microscope). The chemical composition of coating was analyzed by the SEM-EDS method. The 2D surface roughness of single- and double-layer coatings and 3D surface topography maps were examined using a profile measurement gauge. The mechanical properties of coatings were measured by cupping, bending, impact, adhesion to substrate tests run according to standard procedures. As a result, the influence of repainting of polyester powder coatings on their properties was determined. The results demonstrate that repainting has no effect on the microstructure and coating adhesion to substrate as well as the bending test results and roughness of matt and silk gloss coatings. It has been found that repainting affects the results of impact and cupping tests as well as the roughness of samples with fine structure surface finish.

3

Electrostatic powder lubrication for hot massive forming

Gulde M.

Problemy Eksploatacji

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2005

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nr 2

75--82

EN

Growing productivity in the forging industry leads to higher quantities of waste, like lubricant residues, scales and greases. As a consequence, the financial charging for forging companies concerning waste management grows. Investigations showed that the electrostatic powder technology has the potential to lower the amount of lubricants in the process. Today, electrostatic powder lubrication is only established for extrusion moulding of aluminium by using Boron Nitride Powder. Due to high costs of BN-powder, the bad electrostatic chargeability of graphite powder must be improved. An electrostatic powder lubrication system has to be integrated in a production line in the field of hot massive forming.

PL

Rosnąca wydajność w przemyśle kuźniczym prowadzi do zwiększenia ilości odpadów, takich jak pozostałości po smarach, zgorzeliny i tłuszcze. Rezultatem tego są rosnące opłaty za zagospodarowanie odpadów ponoszone przez firmy kuźnicze. Badania wykazały, że wykorzystanie technologii proszków elektrostatycznych może obniżyć zużycie środków smarowych w procesach obróbki na gorąco. Obecnie smarowanie proszkiem elektrostatycznym jest stosowane tylko w przypadku formowania wytłocznego aluminium przy zastosowaniu proszku azotku boru. Ze względu na jego wysoką cenę dąży się do zastąpienia go grafitem. Jednak w takim wypadku należy rozwiązać problem ładowania elektrostatycznego. Umożliwi to włączenie do linii produkcyjnej obróbki na gorąco systemu smarowania grafitowym proszkiem elektrostatycznym.