In-situ Formation of SiC Whiskers by Ni-catalyzed Silicon-modified Pitch and Its Mechanism

摘要

The pitch was dried and modified with 1 mass%nickel nitrate and 10 mass% Si powder successively,then carbonized in Ar atmosphere at 900,1 000,1 100,1 200,1 300,and 1 400 ℃,respectively. Effects of carbonization temperature on phase composition and microstructure of Ni-catalyzed silicon modified pitch were studied by XRD,FESEM and EDS,and the growth mechanism of Si C whiskers was discussed as well. The results show that Si C whiskers form in the carbonized products of modified pitch processed in Ar atmosphere at 1 000,1 100,1 200,1 300,or 1 400 ℃; its length is about1- 6 μm; its growth mode is apical growth,and its growth mechanism accords with V- L- S mechanism.