XU Junkang1, LI Jianbao2, LUO Lijie3, CHEN Yongjun4
(Key Lab of Ministry of Education for Advanced Materials of Tropical Island Resources, College of Materials and Chemical
Engineering, Hainan University, Haikou 570228, Hainan, China)
Abstract: Mullite ceramic precursor powder was first prepared by heating raw materials of Al(OH)3, SiO2 and additives of AlF3 and V2O5 at 1300 ℃. After the addition of yttria-stabilized tetragonal zirconia (8Y-TZP), densified mullite ceramic was obtained by spark plasma sintering (SPS) of the precursor powder at 1300-1600 ℃. The phase and microstructure of precursor powder and densified mullite ceramics were investigated by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the major phase of ceramic precursor powder was mullite, most of which was in the shape of whisker. The mullite precursor (whiskers and grains) began to melt at 941°C during SPS sintering and finally crystallized with flaky morphology.
Key words: mullite; SPS; ZrO2; whisker; co-toughening