| Advanced structural ceramic materials have inherent advantages to challenge extreme service conditions,such as excellent properties such as wear resistance,high temperature resistance,and corrosion resistance.They have become key materials that can replace metals and are widely used in aerospace and advanced nuclear energy.3D printing technology can fabricate the lightweight structure design of ceramic materials,so that people’s research on ceramic materials can more satisfy the needs of practical applications.This article mainly carried out the lightweight design of the sandwich structure of ceramic materials,and successfully prepared a variety of structural sizes of square honeycomb sandwich structure,hexagonal honeycomb sandwich structure and re-entrant hexagonal honeycomb sandwich structure in the auxetic structure using 3D printing technology.The effects of four structural parameters of the hexagonal and square honeycomb sandwich structure of ceramic materials on the mechanical properties were studied by threepoint bending test.The results show that the parameters of the honeycomb core are more important than the parameters of the sandwich face-thickness.While choosing low relative density,high strength and high flexural modulus,the size of the honeycomb core cell can be appropriately reduced and the size of the honeycomb core can be appropriately increased.when the relative density is 40.22%,the bending strength can reach 170 MPa.In general,the mechanical properties of the square honeycomb sandwich structure of zirconia ceramics are better than those of the hexagonal honeycomb sandwich structure.In addition,ceramics are very sensitive to defects formed in the printing preparation process and post-processing process,and the existence of such defects is probabilistic,and they will become strength determining factors.Therefore,there is still a demand for future process optimization.The mechanical properties of the re-entrant hexagonal honeycomb sandwich structure were studied and analyzed through three-point bending test and uniaxial compression test.The results of the three-point bending test show that the re-entrant hexagonal structure has obvious anisotropy,and the mechanical properties in different directions are different.Meanwhile,the L2 structure has better mechanical properties.When the structural design is L2/1.5 and the relative density is 48.6%,the bending strength can reach 206.16 MPa.The uniaxial compression test results show that the structural parameters effect the mechanical properties of the re-entrant hexagonal honeycomb sandwich structure.The Poisson’s ratio of the structure can be changed by design.When the Poisson’s ratio is-2,the strength and elastic modulus reach a low-level peak.When the structural design is-60/1.5 and the relative density is 52.4%,the compressive strength can reach 265.87 MPa.The absorption energy of the reentrant hexagonal honeycomb sandwich structure can reach 27.26 k J,and the specific energy absorption is 4.47 k J/g.The re-entrant hexagonal sandwich structure of ceramic materials can be used as an anti-collision structure to absorb as much energy as possible,and has very good application prospects. |
