Uniformly dispersing GNPs for fabricating graphene-reinforced pure Ti matrix composites with enhanced strength and ductility

Abstract The uniform dispersion of graphene nanoplatelets (GNPs) in the titanium matrix is essential but challenging for preparing high-performance graphene-reinforced titanium matrix composites. This study conveniently dispersed GNPs uniformly in commercial pure titanium (CP Ti) powders by in-situ exfoliating GNPs from high-purity graphite balls via 3D vibration milling and fabricated graphene-reinforced titanium matrix composites (in-situ GNPs/Ti) with improved strength and ductility. Besides, the purchased GNPs were ex-situ introduced into CP Ti through 3D vibration milling as a comparison to investigate the effect of different carbon sources on the uniformity of GNPs distribution. Compared with CP Ti, the ultimate tensile strength, yield strength, elongation, and microhardness of the in-situ GNPs/Ti composite were improved by 42.8%, 20.2%, 12.6% and 9.6%, respectively. The improvements in mechanical properties were mainly attributed to the load transfer of the uniformly dispersed GNPs and the pinning effect of in-situ generated titanium carbide (TiC). Furthermore, it is benefited from considerable strengthening efficiency in this work, the high-purity graphite balls were verified to be a befitting carbon source for 3D vibration milling to introduce GNPs into composites. It could be generalized to fabricating other metal matrix composites reinforced with graphene.