Preparation and Consolidation of Alumina/Graphene Composite Powders

Abstract

Alumina/graphene composite powders were produced by ball milling alumina and graphite for different times. Transmission electron microscopy (TEM) was used to characterize the obtained powders. 3-4 nm graphene sheets were produced after 30 h milling time. Accelerative effect of alumina to ball milling was also studied. Graphene reinforced alumina-based composites were fabricated by spark plasma sintering (SPS) technique from as-prepared powders. Microstructural observation of fracture surface was conducted using scanning electron microscopy (SEM). It was found that adding graphene would hinder grain growth of alumina, making much finer particles.

Graphene NanoPlatelets reinforced tantalum carbide consolidated by spark plasma sintering

“…The TaC-GNP samples display the type of toughening mechanisms observed in the bulk GNP samples, as well those observed in the GNP reinforced composites literature [104][105][106][107][108][109]. Fig.…”

“…GNP is a soft phase and thus a decrease in hardness would be expected in the absence of grain size reduction. It has been observed that GNP that have been ball milled for longer periods and hence reduced in size lead to finer grains in the consolidated structures [105]. Finer grain sizes are expected to strengthen the material however the consolidated structures were not mechanically tested in that study.…”

“…Several studies have been done on alumina [104][105][106] and silicon nitride [107][108][109] based composites reinforced with GNP in order to improve mechanical, thermal, and electrical properties of the ceramic. In the alumina matrix studies graphene sheets are obtained by processing graphite by ball milling or ultrasonication.…”

Spark plasma sintering (SPS) - an advanced sintering technique for structural nanocomposite materials

“…Since the pioneering work of Niihara (1991) (Golla and Basu, 2014;Yamamoto et al, 2008;He et al, 2009;Wang and Steven, 1989;Nieto, Lahiri, and Agarwal, 2012;Liu et al, 2012;Chae et al, 2006;Choa et al, 1998;Gao et al, 1999aGao et al, , 1999bTaya et al, 1990). One of the motivations for interest in SiC-reinforced composites is the toughening mechanism associated with the composites, referred to as residual stress toughening.…”

“…(i) Dispersing a small amount of a harder phase such as SiC, Si 3 N4, and ZrO 2 (ii) Dispersing with a ductile phase such as metallic particles (Cr, Ni, Cu) or high-strength phases such as carbon nanotubes (CNTs) or graphene nanoplatelets (GNPs) (Sergueeva et al, 2009;Yamamoto et al, 2008;He et al, 2009;Wang and Steven, 1989;Nieto, Lahiri, and Agarwal, 2012;Liu et al, 2012;Chae et al, 2006;Choa et al, 1998;Gao et al, 1999aGao et al, , 1999b.…”