Abstract: Al₂O₃ particles possess strong hydrophilicity,which leads to problems including insufficient wet foam stability and poor mechanical properties when preparing pure Al₂O₃ porous ceramics by direct foaming method.Al₂O₃ porous ceramics were prepared through high-speed stirring and foaming using Al₂O₃ as the raw material,heptanoic acid as the foaming agent,and sepiolite fibers (SEPF) as the stabilizing agent,and heat treated at 1 450 ℃ for 2 h.The influence of varying SEPF additions (mass fractions of 0,0.2%,0.4%,0.6%,and 0.8%) on the properties of Al₂O₃ porous ceramics was investigated.The results indicate that as the SEPF addition increases,the cold modulus of rupture and cold compressive strength of the samples initially rise and then fall,while the corrosion depth first decreases and then increase.The sample shows the optimal comprehensive performance when the addition is 0.6%.An appropriate SEPF addition can enhance the stability of the foam slurry and create a multi-level pore structure; the orderly pore structure and dense pore walls can improve the mechanical properties and form a dense isolation layer at the corrosion interface,effectively delaying melt penetration and enhancing the corrosion resistance of the material.

Key words: alumina porous ceramics, direct foaming method, sepiolite fiber, mechanical properties, corrosion resistance

摘要： Al₂O₃颗粒亲水性较强,这使得直接发泡法制备纯Al₂O₃多孔陶瓷,存在湿泡沫稳定性不足、力学性能偏低等难题。以Al₂O₃为原料、庚酸为发泡剂、海泡石纤维(SEPF)为稳泡剂,经高速搅拌发泡,再于1 450 ℃保温2 h热处理制备了Al₂O₃多孔陶瓷。研究SEPF加入量(加入质量分数分别为0、0.2%、0.4%、0.6%、0.8%)对Al₂O₃多孔陶瓷性能的影响。结果表明:随着SEPF加入量的增加,试样的常温抗折强度、耐压强度均先升后降,腐蚀深度则先降后升,当加入量为0.6%(w)时,综合性能最佳。适量SEPF引入可改善泡沫浆料稳定性与多级孔结构,规整的孔径结构和致密的孔壁能提升力学性能,还可在侵蚀界面形成致密隔离层,有效延缓熔体渗透,增强材料抗侵蚀性。

关键词: 氧化铝多孔陶瓷, 直接发泡法, 海泡石纤维, 力学性能, 抗侵蚀性