Finely controlled graded porous Al2O3 ceramics with excellent gas permeability and mechanical properties

In this work, porous ceramics were prepared by foaming-sol-gel-in-situ decomposition method. Pores formed by foaming agent, pores formed by gelation, pores formed by in-situ decomposition of aluminum hydroxide, and pores formed by burning loss of carbon fiber/polypropylene fiber. Through a variety of pore-forming methods, pore structure and distribution can be more accurately controlled. Through-hole porous ceramics with porosity of 54.1 %, compressive strength of 54 MPa, permeability of 3.01 × 10⁻¹⁴ m², high-frequency dielectric constant of 4.01, dielectric loss of 0.001, and pore size of 10–20 μm were prepared. While maintaining high porosity and high strength, the high frequency loss of the traditional alumina sucker is reduced. It provides a better preparation method for the preparation of vacuum ceramic suckers.