短石墨纤维表面溶胶-凝胶法涂覆Al_2O_3

Coating Al_2O_3 on Short Graphite Fibers by Sol-Gel Method

以异丙醇铝为原料,利用溶胶-凝胶法在短石墨纤维表面成功地涂覆了一层厚度约为1~2μm的Al2O3涂层,得到了在石墨短纤维表面制备Al2O3涂层较为合适的工艺条件：pH值为6,勃姆石溶胶浓度为0.4 mol/L,涂覆时间为16 h.采用XRD和SEM对涂层进行表征,结果表明,制备的Al2O3涂层纯净,厚度均匀,与石墨纤维结合紧密;抗氧化性测试结果表明,涂覆Al2O3后,石墨纤维的抗氧化性有了明显的提高.

Taking the aluminium isopropoxide as starting material, the A1203 coating about 1-2μm thick was successfully deposited on short graphite fibers by a sol-gel method. The appropriate process conditions for the Al2O3 coating were obtained, i. e. , pH value is 6, concentration of boehmite sol 0.4 mol/L and coating time 16 hr. The coating was characterized by XRD and SEM, and the results showed that the coating is pure with thickness uniformly distributed, and bonded closely to the surfaces of graphite fibers. The results of antioxidation test indicated that the antioxidability of graphite fibers is improved obviously after coating Al2O3.