面曝光成型薄壁陶瓷BASE管的新型制造方法研究

A Novel Manufacturing Technique of Thin-wall Ceramic BASE Tube by Mask Projection Stereolithography

氧化铝陶瓷固体电解质管(Beta alumina solid electrolyte tube,BASE管)是高温热电转换器能量转换的关键部件。开展了薄壁BASE管的面光源光固化结构成型及其转相工艺研究:开发和制备了体积分数为45%的专用陶瓷浆料,通过浆料光固化性能和曝光参数的试验研究,确定了合适的面曝光成型打印参数;通过素坯的热重曲线分析,建立了脱脂和烧结工艺路线。通过EDS元素分析,烧结后样品仅有Al、O、Zr三种元素;烧结后样品致密度为95.3%,弯曲强度为(352.0±37.5)MPa。以Na2O为钠源开展的转相工艺研究,发现在1 100℃、1 200℃、1 300℃、1 400℃和1 500℃五个温度时转相均有β″-Al2O3的生成,且1500℃时β″-Al2O3生成量为80.5%,其电导率为7.83×10-3S/cm(450℃)。研究了转相对样品致密度、弯曲强度和尺寸精度的影响,发现转相会造成样品致密度的下降。研究表明了面曝光成型技术具有制造薄壁BASE管的可行性,为BASE元件和低成本快速制造Na+电池和碱金属热电转换器提供新的制造手段。

Beta alumina solid electrolyte tube(BASE Tube) is a key component of energy conversion for high temperature thermoelectric converters. This paper developed a mask projection stereolithography method and transformation method to fabricated the thin-walled BASE tube structure. A special ceramic slurry with alumina and zirconia content of 45 vol% is prepared. The slurry curing curve and optimal exposure parameters are analyzed to determine the final printing parameters of the slurry. The thermogravimetric curve analysis is used to develop the degreasing and sintering process route for the ceramic green body. By EDS analysis, Al、O、Zr are the only three elements in the sintered sample. The density and mechanical strength of sintered samples were 95.3% and(352.0 ± 37.5)MPa respectively.The Na2 O is used as the sodium source to explore the phase transformation effect at 1 100 ℃, 1 200 ℃, 1 300 ℃, 1 400 ℃ and 1 500 ℃. The results show that there was generation of β″-Al2 O3 at each temperature section, 1 500 ℃ was the optimal phase conversion temperature, and the production amount of β″-Al2 O3 can be achieved at 80.5 wt% and the ions conductivity at 450 ℃ is 7.83×10-3 S/cm. The effects of phase transformation on sample density, bending strength, and dimensional accuracy were studied. It was found that phase inversion would cause a decrease in sample density. It proved that the feasibility of manufacturing thin-walled BASE tubes by mask projection stereolithography, providing a new manufacturing method for BASE components and low-cost rapid manufacturing of Na+ batteries and alkali metal thermoelectric converters.