EXPERIMENTAL INVESTIGATION EFFECTS OF PARAMETERS OF SPRAY FORMATION ON POROSITY AND HARDNESS


Hasak S. M. A. , USTA Y.

ATOMIZATION AND SPRAYS, cilt.29, sa.9, ss.783-797, 2019 (SCI İndekslerine Giren Dergi) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 29 Konu: 9
  • Basım Tarihi: 2019
  • Doi Numarası: 10.1615/atomizspr.2020031079
  • Dergi Adı: ATOMIZATION AND SPRAYS
  • Sayfa Sayıları: ss.783-797

Özet

In this study, a coating layer has been formed on a cylinder with spray forming technique by using aluminum powders which are atomized by close-coupled nozzles which have been designed and produced before. Since porosity has a major effect on the mechanical properties of spray formed parts, the effect of the parameters on the porosity has been investigated in order to have higher mechanical properties. In the experimental step, a spinning cylindrical tube was located straight forward in the atomization direction. During the experiments, the atomized aluminum powder was sprayed with the help of nozzles when they were yet in the liquid form. The cylindrical tube rotates at a different speed, and the coating has been applied from three different distances, 135, 165, and 200 mm. Therefore, a coating layer was deposited on the cylinder surface. In the study, variable protrusions of 4, 6, and 8 mm at the nozzle tip at 5, 10, and 15 bar pressure were used besides varying the spray distance. Each experimental condition was repeated three times. Samples were taken from the center and side of each coated part in order to examine their porosity, bonding with powders and substrate, powder sizes, and powder shapes using optical microscopy. The effect of newly structured grains on hardness was also examined using a microhardness tester.