Method and apparatus for preparing aluminum matrix composite with high strength, high toughness, and high neutron absorption

A method for preparing an aluminum matrix composite (AMC), wherein through a siphon channel in a center of a melt surface generated by a radial magnetic field, a micro-B4C extrinsic ceramic reinforcement and an intermediate alloy or compound with one or more selected from the group consisting of B, Cd, Hf, Ti, and Zr are introduced into a melt, and a temperature and a pressure caused by cavitation and acoustic streaming generated through an ultrasonic field below a liquid surface of the siphon channel help to achieve infiltration and dispersion of the micro-B4C extrinsic ceramic reinforcement and promote generation of an in-situ nano-reinforcement from the intermediate alloy or compound with one or more selected from the group consisting of B, Cd, Hf, Ti, and Zr and uniform dispersion of the in-situ nano-reinforcement, such that the aluminum matrix composite reinforced by a cross-scale hybrid of the micro-B4C extrinsic ceramic reinforcement and the in-situ nano-reinforcement is prepared, wherein a micro-B4C powder of the micro-B4C extrinsic ceramic reinforcement comprises B4C microparticles with a B4C content of 98.8 wt % or more and an average particle size of 10 μm to 300 μm, and a volume fraction of the B4C microparticles in the AMC is 5 vol % to 30 vol %, and wherein the in-situ nano-reinforcement with one or more selected from the group consisting of B, Cd, Hf, Ti, and Zr comprises one or more selected from the group consisting of ZrB2, TiB2, CdB, and HfB2 that are generated by introducing different intermediate alloys or reactants in the melt for an in-situ reaction, the in-situ nano-reinforcement comprises in-situ nano-reinforcement particles with a particle size of 2 nm to 100 nm;

• and a volume fraction of the in-situ nano-reinforcement particles in the AMC is 0.2 vol % to 25 vol %,
• the method specifically comprises the following steps:
• step 1:
• melting a matrix aluminum alloy in a crucible of an integrated composite preparation apparatus at 850° C. to 950° C. to obtain a melt;
• step 2:
• turning on a radial magnetic field device and an ultrasonic device of the integrated composite preparation apparatus, and adding the intermediate alloy or compound with one or more selected from the group consisting of B, Cd, Hf, Ti, and Zr mixed in a predetermined ratio through a feed pipe to conduct a reaction for 20 min to 30 min, to generate the in-situ nano-reinforcement;
• and
• step 3:
• cooling the melt to 780° C. to 800° C., adding the B4C microparticles through the feed pipe, and applying the radial magnetic field and the ultrasonic field to promote infiltration and dispersion of the B4C microparticles in the composite melt;
• and stirring for 10 min to 30 min, cooling to 720° C. to 750° C., followed by casting.