Structure and Properties of Biomorphous Al/C/TiO/TiC Composite Materials Reinforced with Charcoals Coated in ALD and the Sol-Gel Process

Abstract

In this framework, an investigation of biomorphous composite materials was performed. The application of a natural reinforcement allows to obtain biomorphous composite materials. Pine wood samples were subjected to the pyrolysis process in order to obtain carbon char. The samples were subjected to Atomic Layer Deposition and the sol-gel coating process in order to obtain a titanium oxide and titanium carbide coating, respectively. Ti-gel carbon char samples were subjected to ceramisation. Pure carbon char coated with TiO and TiC was infiltrated with an Al alloy. The investigations of the obtained composite materials were performed using light microscopy, transmission and scanning electron microscopy for microstructure determination. Raman spectroscopy and X-ray analysis were performed, along with hardness and tribological tests. Crystallites were detected after infiltration of the porous samples with an Al alloy, which were up to several microns in size, depending on the selected coating. As a result of the investigation on coating samples, a significantly smaller presence of Al carbides was found. An increase of hardness and wear resistance of biomorphous composite materials containing the carbides phase was confirmed. The TiO2coating prevents the occurrence of a reaction during the infiltration process and the formation of Al carbides.