Preparation And Properties Characterization Of Alumina Ceramic Continuous Fibers

Alumina continuous fibers has aroused extensive attention of researchers because it owns both spinnability as fiber and heat-resistance,corrosion-resistance as aluminum oxide ceramics.In this paper,yttium aluminum Gamet(YAG)continuous fibers and alumina-zirconium continuous fibers were prepared by sol-gel technology and dry spinning technology.The preparation process of spinnable sol,fiber preparation,the ceramization process of fibers,microstructure of calcined fibers and their mechanical properties were discussed.On the one hand,prepare and research alumina continuous fibers could fill the blank of alumina continuous fibers preparation in the domestic,on the other hand it have a great role in promoting the development of China's advanced ceramic materials.1.Preparation and characterization of alumina-zirconium ceramic continuous fibersIn this study,alumina-zirconium ceramic continuous fibers were fabricated by dry spinning technology and heat treatment technology.Flexible fibers were fabricated with aluminum salt,aluminum powder and y-AIOOH as aluminum source,zirconium acetate as zirconium source and PVP as spinning additives.The fibers were characterized by TG-DSC,XRD,IR,TEM,SEM,respectively.The effect of the spinning process and the ceramic process on the mechanical properties of continuous fiber was studied.The experiment showed that the smaller the diameter of the fiber,and following the greater breaking strength of ceramic fiber.During the sintering process,a slower heating rate is used in the low temperature stage,and a faster heating rate and a shorter holding time are used in the high temperature stage to obtain dense fibers with smaller crystal grains,which is beneficial to increase the fiber breaking strength.The average diameter of the alumina-zirconium ceramic continuous fibers is 8-9?m.Under optimal condition,the mean breaking strength of the fiber is 2.15GPa This kind of alumina-zirconium ceramic continuous fibers with high breaking strength has important application in aerospace industry.2.Preparation and characterization of yttium aluminum Garnet continuous fibersIn this study,yttium aluminum Garnet continuous fibers were prepared by sol-gel combined dry spinning technology.The progress of fibers formation,characterization and mechanical properties were researched.The sol was prepared after mixing and vacuum distillation with alumina sol,yttria sol,acetic acid and PVP as the raw materials.Gel continuous fibers were prepared using a dry spinning technique,followed by heat treatment to obtain yttrium-aluminum garnet continuous fibers with a diameter of 8?m.The fibers were characterized by TG-DSC,XRD,IR,TEM,SEM,respectively.The experiment showed that the precursor sol prepared by the sol-gel method is uniform and stable,and can be stored for a long time.The length of gel fibers prepared by dry spinning were 2000 meters.The surface of the fibers after heat treatment is smooth and the internal structure is tight.The fibers have high strength and flexibility.Under optimal condition,the mean breaking strength of the fiber is 1.00 GPa.The experimental process is simple,the production cycle is short,and it is easy to realize industrialization.