Preparation and mechanism analysis of a new type hollow multiphase ceramic micro-spheres

Self-reactive quenching technology and Al + Cr2O3 + Si + Sucrose + Epoxy Resin as reaction system are used to prepare hollow multiphase ceramic micro-spheres. Forming mechanism of the quenching products is analyzed through high-speed photography, water quenching method, SEM, XRD and EDS. The results show that agglomerate powders go through three phases during the flight process in flame field: heated ignition, ceramic droplets formed and cooled rapidly. The quenching products consist of two parts: one is the hollow irregular porous particles; the other is the hollow ceramic micro-spheres with smooth surface. The high heat released from aluminothermic reaction guarantees the forming of hollow multiphase ceramic micro-spheres and SiC. The porous, open and hollow structure is essentially caused by the large volume of gas formed during the reaction process.

This graphical shows the preparation principle of hollow multiphase ceramic micro-spheres. The agglomerate powder is sprayed through the gun, and self-propagating high temperature synthesis reactions occur during the spraying process. Large volume of gas and ceramic droplets are formed. The gas can not escape from the inside of droplets in the cooling process. The hollow structure is obtained.Figure optionsDownload as PowerPoint slideHighlights
► Al + Cr2O3 + Si + Sucrose + Epoxy Resin as reactive system.
► Self-reactive quenching technology as a new method of preparing micro-spheres.
► Hollow multiphase ceramic micro-spheres were prepared successfully.
► The mechanism was analyzed by high speed photography and water quenching method.