Selective laser melting of graphene reinforced titanium matrix composites: Powder preparation and its formability

Graphene is an attractive reinforcement in enhancing performances of titanium matrix composites (TMCs). However, the fabrication of graphene reinforced TMCs components is challenging to conventional manufacturing technologies. Selective laser melting (SLM) shows great potential in fabrication of TMCs components. In this study, SLM was employed to fabricate graphene reinforced TMCs, and the effects of ball milling time on properties of composite powder and resultant SLM formability were investigated. The morphologies, chemical composition, flowability and phase constitute of composite powder were evaluated by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Hall flowmeter and X-ray diffraction (XRD), respectively. The structure of graphene in composite powder was assessed by Raman spectroscopy. The formability of SLM scanning-track using different composite powder was also studied. The results showed that the composite powder, milled for 5 h, possessed good sphericity, good flowability and well-dispersion of graphene. Finally, the SLM-processed graphene reinforced TMCs, using the optimized composite powder, exhibited higher microhardness of 432.03 HV0.2, higher tensile strength of 1276 MPa and lower coefficient of friction of 0.3453 than that of the SLM-processed TC4, revealing the great improvement in mechanical performance of the SLM-processed TMCs by adding graphene. (C) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

Automated summary

Graphene is used as reinforcement in titanium matrix composites (TMCs) to enhance performance, with selective laser melting (SLM) showing great potential in fabrication. The study investigated the effects of ball milling time on properties of composite powder and formability of SLM. Results showed that 5-hour ball-milled composite powder had good sphericity and flowability. The optimized SLM-processed graphene reinforced TMCs exhibited higher microhardness and tensile strength compared to SLM-processed TC4.