Akademik Veri Yönetim Sistemi
International Pumice and Perlite Symposium, Bitlis, Türkiye, 4 - 06 Kasım 2021, ss.12-13
In the present study, it was investigated whether pumice powder, which is an unusual (non-traditional)
reinforcement material for metals, can be used in the production of magnesium-based composites. For this
purpose, magnesium matrix composite materials reinforced with pumice were produced by hot pressing method.
The dimensions of the starting magnesium and pumice powders were smaller than 45 μm. The pumicemagnesium
powder mixtures containing 10% reinforcement by volume were subjected to hot pressing under
protective argon gas for 1 hour under 50 MPa pressure at 550 °C in graphite molds. Since thermodynamic
calculations show that it is possible to reduce SiO2by magnesium in completely solid state at 550 °C, it is aimed
to produce Mg2Si and MgO reinforced magnesium matrix composite materials by in-situ method as a result of
the chemical reaction of pure magnesium with SiO2 in the pumice. The density of the produced composite
materials was determined by the Archimedes’ method, the phases present in the microstructure were determined
by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyzes. The hardness of the produced
composite material and that of pure magnesium were determined by Micro-Vickers hardness measurements. As
a result of XRD and SEM analysis, it was observed that there were magnesium, Mg2Si, MgO, and oxide phases
present in the raw pumice powders in the composite microstructure. It was determined that the hardness of the
matrix phase of the composite material, which has a density value close to the full density, increased approximately 26% compared to pure magnesium. In the light of the results obtained, it is concluded that pumice
can be used as a reinforcement material in the production of magnesium-based composite materials, considering
its low density and low cost, and that the developed composite materials can be used in industrial applications
such as automotive and aerospace where low density is an important parameter.
Keywords: Magnesium matrix composites, Pumice, Hot pressing, Microstructure, Mg2Si, MgO