JIANG Sansheng 1, ZHOU Yang 2
(1. School of Mechanical and Electronic Engineering, Beijing Agricultural Vocational College, Beijing 102208, China;
2. School of Mechanical, Electronic & Control Engineering, Beijing Jiaotong University, Beijing 100044, China)
Abstract: Preparation of high quality Si3N4/Si green body by gelcasting is the premise and key to obtain the Si3N4 wave-transmitting materials with good properties, the gelcasting process of Si3N4/Si green body and configuration parameters of Si3N4/Si slurry were determined by experiment. The influence of the dispersant on slurry fluidity and stability was analyzed. The surface morphologies and performance of Si3N4/Si gel-body with different composition designs were analyzed. It is suggested that the composition of Si3N4/Si had important influence on the quality of its body and sintering products, the density and bending strength of the green body increased with the increase of Si3N4 content (the maximum was 12.01 MPa). When the sintering temperature was 1450 ℃ (the soaking time was five hours), the bending strength of the sample containing 35wt.% Si3N4-5wt.%SA-Si was the largest (130.2 MPa), the dielectric constant of the sample containing 80wt.% Si3N4-5wt.%SA-Si was the best (4.893).
Key words: Si3N4/Si; gelcasting; preparation of green body; SEM; performance analysis