Composite containing hollow ceramic spheres and preparation method of composite

A 3D printing method for an impact-resistant gradient complex part containing a hollow ceramic sphere complex, wherein the method comprises the following steps:

• 1) designing the size and shape of the part as well as an internal layered structure;
• 2) providing two raw materials, wherein one of the two raw materials is metal powder, and the other raw material is hollow ceramic spheres;
• 3) providing the metal powder with a certain thickness according to a design, melting the powder by using a heat source and then solidifying to form a solidified metal layer, and repeatedly printing solidified metal layers according to the design until a metal layer with a designed thickness is formed;
• 4) providing a layer of hollow ceramic spheres on the surface of the metal layer, providing the metal powder until gaps among all the spheres are filled, melting the powder by using the heat source and then solidifying to form a solidified metal-ceramic sphere complex layer, and repeatedly printing solidified metal-ceramic sphere complex layers until a complex layer with a designed thickness is formed;
• and
• 5) repeating steps 3) and 4) to form the impact-resistant gradient complex part,
• wherein the diameters of the hollow ceramic spheres range from 50 μm to 5 mm, and the ratio of wall thicknesses to radiuses of the hollow ceramic spheres is ⅓ to ⅔;
• a breakage rate of the hollow ceramic spheres is smaller than 5% when the pressure is higher than 86 MPa;
• the hollow ceramic spheres comprise SiO2 hollow spheres, corundum (Al2O3) hollow spheres, mullite hollow spheres and hollow spheres comprising a mixture of corundum and glass;
• and
• the metal powder comprises aluminum powder and titanium powder.