Impulse mechanical strength improvement of alumina by surface coating

Abstract

To increase the impulse mechanical strength of alumina, the pore structure of alumina was modified by surface coating. It was found that the impulse mechanical strength of alumina samples coated with aluminum chloride increases from 35 MPa to 51 MPa and the mechanical strength of alumina samples coated with aluminum-based complex increases from 21 MPa to 46 MPa at the calcination temperature range of 100 ℃ to 1100 ℃ by the DL-3 typed impulse mechanical strength test device, while the mechanical strength of uncoated alumina samples increases from 17 MPa to 39 MPa. According to scanning electron microscopy and X-ray diffraction, the surface coating of aluminum chloride has little influence on the crystal type of alumina materials after high temperature calcination. At the same time, it can effectively fill the matrix pore of alumina materials, increase the density of the support, and improve the mechanical strength of alumina materials. In addition, compared with the alumina sample coated with aluminum complex, the alumina material coated with aluminum chloride possesses larger surface area and smaller pore size after high temperature calcination. More importantly, the surface of the alumina sample coated with aluminum chloride formed a rough shape after high temperature calcination, which was beneficial to the loading and dispersion of the active metals.

Keywords

• alumina
• impulse mechanical strength
• surface coating
• aluminum chloride