Layered Grain Growth of Aluminum Between MWCNT Layers During Sintering of Al–MWCNT Composites

Abstract

The present study demonstrates how layered grain growth evolved in aluminum during sintering, of Al–MWCNT composites prepared through mechanical alloying. Mechanical alloying of aluminum and MWCNT produced a flake-shaped lamellar particle by flattening panicles and welding them together, and random welding produced lamellar granules. MWCNT lamellas limit the grain growth resulting in a 2D layer of aluminum between the MWCNTs during sintering. By adding more MWCNTs into aluminum, the interlayer thickness of layered composites was refined. The layer thickness of aluminum is 2.5 cm in Al–0.20 wt% MWCNT, 1.0 By adding more MWCNTs into aluminum, the interlayer thickness of layered composites was refined. The layer thickness of aluminum is 2.5 μm in Al–0.20 wt% MWCNT, 1.0 μm in Al–0.50 wt% MWCNT, and about 0.8 μm in Al–1.0 wt% MWCNT. In addition to the grain refinement and hardening effects of MWCNTs, the sintered composites exhibit increased hardness with increasing the CNT concentration in the composite.