【摘要】 采用85%磷酸和氧化铝制备了低温固化的烧蚀基体——磷酸铝溶液。通过Brookfield流变仪监测体系的粘度变化;借助X射线衍射分析研究影响磷酸铝基体组成的两个主要因素,即Al/P比例和反应温度。结果表明,A l/P比例控制在1.3∶3~1.4∶3之间,反应温度不高于110℃时可获得性能良好的磷酸铝基体。XRD研究结果表明,磷酸铝溶液的过早硬化主要是由于AlPO4.xH2O沉淀引起的。使用螯合剂可有效抑制过早硬化,加入约2%草酸,2个月左右后溶液中可溶性磷酸盐百分含量为84%,基本满足使用需求。草酸的引入对高硅氧布/磷酸铝复合材料的强度基本没有影响。更多还原

【Abstract】 The ablative matrix cured under low temperature—aluminium phosphate was prepared with 85% phosphoric acid and alumina.The viscosity profile of the system was measured by using Brookfield rheometer.Two main factors of the matrix ingredient were studied by X-ray diffraction(XRD) analysis,such as the Al/P ratio and temperature.The results show that aluminium phosphate matrix with excellent properties can be obtained when Al/P ratio is within 1.3∶3～1.4∶3,and reaction temperature is less than 110 ℃.XRD analysis shows that premature hardening is due to precipitation of insoluble aluminium phosphate.A sequestrant can be used to effectively prevent premature hardening.When 2% oxalic acid was added into solution,the percent of soluble phosphate after two months is 84%,which can meet use demands.The addition of oxalic acid has little effect on the strength of high Si-O fiber fabric/aluminium phosphate composites.更多还原