【摘要】 研究了制备β″-Al₂O₃陶瓷粉料的喷雾干燥工艺,选择了Al₂O₃-LiOH·NaOH水溶液泥浆的喷雾干燥工艺。仅0.25wt％的木质素磺酸盐或0.5wt％的阿拉伯胶,即可使Al₂O₃含量达45wt％左右的泥浆的相对粘度降至2以下。这种喷雾干燥粉料的松装密度d₁为0.8—0.9g/cm³,振实密度d_t在1.0g/cm³上下,流动度达25—27cm³/s·cm²。直接用这种粉料压坯,可制出烧结密度高于3.21g/cm³,300℃电阻率6—7Ω·cm的β″-Al₂O₃陶瓷管。其它碱源的粉料则须经煅烧后再压坯方能烧结到较高的密度。更多还原

【Abstract】 Spray drying as a method for preparing β″-Al₂O₃ powders has been investigated. A kind of spray drying technique using for Al₂O₃-LiOH.NaOH solution slurry was selected after compared the properties of several spray-dried powders prepared by different approches. The relative viscosity of this water based alkaline slurry containing about 45wt% Al₂O₃ can be lowered to a value less than 2 by adding 0.25wt％ lignosulfonates or 0.5 wt％ gum arabic. Spray-dried powder with loose density of 0.8—0.9g/cm³. tap density of 1.0g/cm² and fluidity of 25—27cm³/s.cm² has been prepared from the above slurry. Without calcination, this kind of powder can be isostatically pressed and then sintered to a density of 3.21g/cm². The Na ion resistivity of the sintered sample is 6—7Ω·cm st 300℃. Spray-dried powders using other salts as alkali sources have to be calcinated before pressing to obtain a higher fired density更多还原