KD-Ⅱ和Hi-Nicalon纤维热处理后的力学性能

摘要

This paper studies the tensile properties of both silicon carbide fibers of KD-Ⅱ and Hi-Nicalon under heat treatment of 1,400-1,600℃ for lh in the argon atmosphere and at 1,100-1,400℃ for 1-100h in air,respectively.Results indicate that both fibers have similar strength and strength degradation during the heat treatment,and can endure a higher temperature in inert atmosphere,while the strengths of the fibers decrease with the increase of time or temperature in air heat treatment.Compared to Hi-Nicalon,KD-Ⅱ fiber exhibits a higher oxidation rate and a lower active energy.%研究了KD-Ⅱ和Hi-Nicalon两种连续碳化硅纤维在氩气氛下1400～1600℃保温1h和空气中1100 ～1400℃保温1～100h后的力学性能.结果表明,两种纤维热处理前后强度相当,下降趋势相似;两种纤维在惰性气氛下能耐较高温度,在空气中热处理时随着时间的增加或者温度升高,纤维强度逐渐下降.与Hi-Niclaon相比,KD-Ⅱ纤维氧化速率较快,氧化反应活化能略低.