高温处理对几种玄武岩纤维成分和拉伸性能的影响

Effects of Elevated Temperature Treatment on Compositions and Tensile Properties of Several Kinds of Basalt Fibers

选取5种国产玄武岩纤维,采用X射线荧光光谱法和纤维单丝拉伸测试等方法,研究200~800℃空气气氛和氮气气氛处理前后纤维的化学成分、物理特性和拉伸性能等变化,以揭示玄武岩纤维的耐高温性能。结果表明:空气气氛下高温处理后由于表面处理剂的去除,玄武岩纤维表面更加光滑,直径略微变小,同时质量减少;SiO_2,Al_2O_3质量分数减小,而FeO+Fe_2O_3,CaO,MgO质量分数都增大,其中FeO+Fe_2O_3的质量分数增加最多,增幅最大达到21%。200℃处理后玄武岩纤维单丝拉伸强度有一定降低,强度保留率最大为98.3%,400℃处理后强度明显下降,强度保留率最高达到64.6%,800℃处理后强度保留率均不足20%。此外,纤维断裂伸长率随温度的升高而减小,弹性模量增大。与空气气氛相比,氮气气氛下纤维强度保留率更高,拉伸性能更稳定。

Five kinds of domestic basalt fibers were studied for the changes of chemical compositions, physical properties and tensile properties of these fibers before and after 200-800℃ treatment in air at- mosphere and in nitrogen atmosphere. These works were done mainly by means of X-ray fluorescence spectrometry and fiber monofilament tensile testing methods in order to understand the elevated tem- perature resistance of basalt fiber. The experimental results show that the surface of basalt fibers be- comes smoother with slightly smaller in diameter and mass reduction at the same time, due to the re- moval of fiber surface treatment agent after elevated temperature treatment in air atmosphere. Mass fractions of SiO2 and Al2O3 decrease while mass fractions of FeO＋Fe2O3, CaO and MgO increase, among which the mass fraction of FeO＋Fe2O3 increase the most with the maximum increase of 21%. The monofilament tensile strength of basalt fiber is reduced after 200℃ treatment and the maximum strength retention percentage is 98. 3%. The monofilament tensile strength reduces evidently after 400℃ treatment and the maximum strength retention percentage is 64. 6%. Moreover, the strength retention percentages of five kinds of basalt fibers are all less than 20% after 800℃ treatment. In ad- dition, the fiber elongation at break decreases with the increase of treating temperature and the elastic modulus increases. Compared with that in air atmosphere, strength retention rate of basalt fiber is higher and tensile properties are more stable in nitrogen atmosphere.