The effect of milling time, milling speed and ball to powder weight ratio on the physical properties of submicron Al2O3 ceramic particles fabricated by mechanical milling method


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VAROL T.

PAMUKKALE UNIVERSITY JOURNAL OF ENGINEERING SCIENCES-PAMUKKALE UNIVERSITESI MUHENDISLIK BILIMLERI DERGISI, vol.24, no.4, pp.635-642, 2018 (ESCI) identifier

Abstract

The aim of this study is the fabrication of submicron and nano Al2O3 ceramic powders from coarse Al2O3 (Alumina) ceramic powders by mechanical milling method. The effect of mechanical milling parameters such as milling time, milling speed and ball to powder weight ratio on the morphology, particle size, specific wear rate, apparent density and microstructure of milled coarse Al2O3 powders is also investigated. Scanning electron microscope is used for morphology examination. The average particle size and specific surface area are investigated by a particle sizer. The apparent density values are measured by using a hall flowmeter. Morphology examinations showed that the polygonal morphology of Al2O3 powders is changed to irregular and spherical morphology with increasing milling speed. When the particle size values investigated, it is found that the most effective parameter for particle size refinement is the milling speed. The lowest particle size of Al2O3 powders is 320 nm which is obtained with 300 rpm of milling speed, 5h of milling time and 15: 1 of ball to powder weight ratio. When the initial size of the Al2O3 powders with 48 micron and 320 nm of final particle size at obtained at the 5h of milling are compared, the effect of mechanical milling on the milling process of ceramic powders is clearly demonstrated.