ZHANG Meng ¹, HUANG Juntong ^1,2, HU Zhihui ¹, XIONG Qingming ¹, FENG Zhijun ¹, CHEN Zhi ¹, YAN Mingge ¹, LI Xibao ¹
(1. School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 300063, Jiangxi, China; 2. School of Materials and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China)

Abstract: Sialon powders with fibers were successfully prepared by using Si powder, Al powder and Al₂O₃ powder as raw materials and Ni powder as catalyst. Effects of temperature (1300~1450 °C) and content of Ni (0~7.5wt.%) on weight gain rate, phase composition and microstructure ofproducts were studied. The addition of Ni resulted in the increasing of the weight gain rate of the products by 1.3~3.9 times, which indicated Ni greatly promoted the degree of nitridation. Addition of Ni reduced the complete-nitridation temperature of Si over 100 °C as well as the synthesis temperature of Sialon. The appropriate content of Ni should be 1.25~2.5 wt.%, more than that would lead to the decrease of weight gain rate. Ni-containing spheres on the tips ofSialon fibers were found in the products, indicating that Ni promoted the formation of Sialon one-dimensional nanostructures through VLS mechanism.

Keywords: Sialon; transition metal catalyst; weight gain rate; promoting the nitridation; fibers