Graphene- and in-situ nanoparticle-reinforced aluminum-based composite material and preparation method

A preparation method of a graphene and in-situ nanoparticle-co-reinforced aluminum matrix composite, comprising:

• heating an aluminum alloy for melting, adding potassium fluoroborate and potassium fluorozirconate to produce in-situ nano-ZrB2 particles, additionally adding a mixture of pre-prepared copper-coated graphene nanosheets and an aluminum powder, followed by stirring with an electromagnetic field for an uniform dispersion to obtain a resulting melt;
• and ultrasonically treating the resulting melt to improve a dispersion of the in-situ nano-ZrB2 particles and the pre-prepared copper-coated graphene nanosheets, followed by casting for molding to obtain a casting, and subjecting the casting to homogenization and rolling for a deformation to obtain a graphene and in-situ nano-ZrB2 particle-co-reinforced aluminum matrix composite, wherein the preparation method specifically comprises the following steps:
• (1) a pretreatment of raw materials for producing the nano-ZrB2 particles:
• taking and thoroughly mixing the potassium fluoroborate and the potassium fluorozirconate according to a molar ratio of (2-2.1):1 to obtain a first resulting mixture, and preheating the first resulting mixture to 300° C. to 500° C. for later use;
• (2) a preparation of the pre-prepared copper-coated graphene;
• (3) a mixing of copper-coated graphene and the aluminum powder:
• mixing and ball-milling the copper-coated graphene and the aluminum powder for 1 h to 3 h in a ball mill under an Ar atmosphere according to a mass ratio of 1:(1-2) to obtain a mixture;
• (4) a preparation of an as-cast aluminum matrix composite:
• heating an aluminum alloy melt to 850° C. to 900° C., adding pretreated potassium fluoroborate and potassium fluorozirconate to allow a reaction for 25 min to 30 min to produce the nano-ZrB2 particles, during the reaction, an electromagnetic stirring is conducted for a particle dispersion;
• cooling to a predetermined temperature, and adding the mixture of the copper-coated graphene and the aluminum powder to the aluminum alloy melt under a mechanical stirring to obtain a second resulting mixture;
• and subjecting the second resulting mixture to an ultrasonic treatment, and casting to obtain the as-cast aluminum matrix composite;
• (5) a homogenization:
• keeping the as-cast aluminum matrix composite at 560° C. for 20 h to 25 h;
• and
• (6) a rolling:
• rolling a homogenized composite at 450° C. to 480° C. for the deformation to finally obtain the graphene and in-situ nano-ZrB2 particle-co-reinforced aluminum matrix composite;
• wherein in the graphene and in-situ nano-ZrB2 particle-co-reinforced aluminum matrix composite, a content of the copper-coated graphene is 0.01 wt. % to 1 wt. %, a content of the nano-ZrB2 particles is 0.01 wt. % to 3 wt. %, and the balance is an AA6111 aluminum alloy.