A general method to synthesize and sinter bulk ceramics in seconds

Abstract

Ceramics are an important class of materials with widespread applications because of their high thermal, mechanical, and chemical stability. Computational predictions based on first principles methods can be a valuable tool in accelerating materials discovery to develop improved ceramics. It is essential to experimentally confirm the material properties of such predictions. However, materials screening rates are limited by the long processing times and the poor compositional control from volatile element loss in conventional ceramic sintering techniques. To overcome these limitations, we developed an ultrafast high-temperature sintering (UHS) process for the fabrication of ceramic materials by radiative heating under an inert atmosphere. We provide several examples of the UHS process to demonstrate its potential utility and applications, including advancements in solid-state electrolytes, multicomponent structures, and high-throughput materials screening.

All ceramic cathode composite design and manufacturing towards low interfacial resistance for garnet-based solid-state lithium batteries

“…37 With additives, there has been a promising report; 19 however, further engineering to achieve reduced additive loading or alternative processing such as additive coatings on cathode particles is required. Regardless of the cathode preparation methods, ultra-fast sintering strategies 83,84 can further help to achieve chemically sharp but metallically strong-enough interfacial bonding for enhanced performance especially for all-oxide cathode composites for SSBs. With society's need for low-cost and mass-manufacturable processing for cathode composites, we conclude that the presented procedure is inexpensive, rapid, and potentially adaptable for large-scale Three different types of all-oxide cathodes are categorized with respect to the processing strategies: (i) all-oxide cathode w/additives, 19,32,36 (ii) all-oxide cathode without porous LLZO, 37 and (iii) all-oxide cathode with porous LLZO.…”

Materials research & measurement needs for ceramics additive manufacturing

“…Most recently, after this workshop, a new densification technique called ultrafast high-temperature sintering (UHS) has been reported. 61 In this method, a part to be sintered is sandwiched between two carbon tapes through which electric current is passed, providing rapid (seconds) heating up to temperatures as high as 3000°C. The process is performed in an inert atmosphere.…”

Radionuclides from Nature to Nature: Recent Progress in Immobilization of High Level Nuclear Wastes in SYNROC

“…广泛关注 [11][12][13][14][15] 点的不足, 可以提高对核素的包容量和普适性 [16] 。 目前我国在矿物相作为人造岩石固化体方面的 研究也取得了丰硕的成果。兰州大学李玉虹等 [17][18][19] [20][21] 采用加压/烧结的方法, 加入水铝英石, 得到 了稳定的 Cs 凝固产物; 并通过加压/烧结法, 添加 天然的水铝英石和丝光沸石得到稳定废铯吸附剂固 化体。笔者等 [22][23] 从合成、固溶量、微观结构、化 学耐久性等方面对锆石模拟固化 Nd 和 Ce 进行了系 统的研究; 卢喜瑞等 [24] 研究了 Gd 2 Zr 2 O 7 烧绿石固化 Ce、U 等锕系核素的耐辐照能力及其相关性质; 张 魁宝等 [25] 对钙钛锆石、独居石等进行了研究。中国 工程物理研究院 Zhang 等 [26] 研究了固化三价次锕系 Np(Sm)氟磷灰石型固溶体。此外, 中国原子能科学 研究院也研究了烧绿石、钙钛锆石、钛酸盐陶瓷等 陶瓷固化体 [27][28][29][30] [32] Fig. 4 Temperature gradient model of zircon interface by using microwave synthesis [32] 放电等离子烧结(Spark Plasma sintering, SPS)又 称为等离子辅助烧结(Plasma Activated), 是在粉末 颗粒间直接通入脉冲电流进行加热烧结, 具有加热 均匀、升温速度快、烧结温度低(比热压烧结可降低 100~200 ℃)、烧结时间短、生产效率高、致密度高 等特点。近年, 该方法在 SYNROC 固化体烧结方面 展现出良好的工程化前景。Wang 等 [34] 采用该方法 成功在 1600~1700 ℃, 80 MPa, 3 min 条件下, 在 Gd 2-x Nd x Zr 2-y Ce y O 7 (0≤x, y≤2.0)固化体中完成了 Nd 和 Ce 的共掺杂。 熔盐合成法(Molten salt synthesis, MSS)采用低 熔点的一种盐类或多种盐组成低熔点盐类体系作为 反应介质, 合成过程中出现液相, 反应物在熔盐中 有一定的溶解度, 加快了离子的扩散速率, 使得反 应在原子级进行。该法相对于常规固相法而言, 具 有制备方法简单, 不需要复杂的程序和危险的试剂, 能有效降低合成温度和反应时间, 制备的粉体化学 成分均匀、晶体形貌好、物相纯度高、熔盐可重复 使用等优点 [35] , 在 MAX [36] 、MXenes [37] 、二维层状 材料 [38] 、陶瓷固化体 [39][40] 等材料合成方面具有独特 优势。 Wu 等 [39] [48] 利用超高温烧结 技术, 直接在数秒内合成块体陶瓷材料, 大大提高 了材料的合成速度, 改善了材料质量, 见图 5。超高 温烧结技术的特点是温度分布均匀, 加热速度(10 3~ 10 4 ℃/min)和冷却速度(高达 10 4 ℃/min)超快, 并且 烧结温度高(高达 3000 ℃)。 超高的升温速率和超高 图 5 碳热冲击超高温快速烧结 [48] Fig. 5 Carbon thermal shock ultra-high temperature rapid sintering [48] 温使超快烧结时间达到约 10 s, 极大提升了材料的 合成速度, 使得高通量材料筛选成为可能。超高的 温度、超快的加热速度和退火速度提高了材料的烧 结质量。该方法在人造岩石(陶瓷)固化尤其是对易 挥发性核素固化方面具有潜在应用前景。 与此同时, 还要考虑到低熔点放射性核素的特 殊性, 诸如放射性碘在 500 ℃时容易从相关化合物 中挥发出来, 所选固化类方法必须在...…”