Ultrafast joining of zirconia ceramics using electric field at low temperatures

Electric field‐assisted solid‐state reaction of BaCO3‐TiO2 system

“…In the past decade, flash sintering behavior and/or flash events have been reported in different classes of ceramics, including metallic conductors, ionic conductors, semiconductors, and room temperature insulators. 2,3 Besides being employed to simply densify ceramics, flash sintering technique has been adopted in other applications, such as flash joining, 4,5 super-plastic deformations, 6 and reactive flash sintering. 7,8 In reactive flash sintering, chemical reactions can be dramatically accelerated, and densification occurs along with chemical reactions in a single run.…”

DC‐driven ultrafast transient liquid phase bonding of 3YSZ and GH3128 superalloy using Ni interlayer

“…When the energization time was less than or equal to 30 s, the joints fractured at 3YSZ/Ni interface and in 3YSZ substrate (Figure 5A). However, when the energization time was greater than or equal to 45 s, a considerable quantity of oxygen vacancies generated and accumulated to form pores in 3YSZ (Figure 4D,E), which severely deteriorated the strength of 3YSZ 27,28 . Consequently, the joints fractured in 3YSZ substrate (Figure 5B), accompanied by an obvious decrease in shear strength.…”

“…However, when the energization time was greater than or equal to 45 s, a considerable quantity of oxygen vacancies generated and accumulated to form pores in 3YSZ (Figure 4D,E), which severely deteriorated the strength of 3YSZ. 27,28 Consequently, the joints fractured in 3YSZ substrate (Figure 5B), accompanied by an obvious decrease in shear strength. XRD analysis at the fracture surfaces of 3YSZ side in the joints obtained at 15 s and 30 s showed the presence of Ni 5 Zr and Ni 7 Zr 2 phases (Figure 5C), which was consistent with the aforementioned EDS analysis results.…”

Research Progress on the Flash Sintering Mechanism of Oxide Ceramics and Its Application

“…基于闪烧过程中由临界电场所激发的低温快速 传质，本团队发明了同种陶瓷/陶瓷、陶瓷/金属，甚 至异种陶瓷/陶瓷之间快速连接的闪焊技术。利用闪 焊技术， 我们实现了3YSZ陶瓷和镍基高温合金之间 的连接 [14] ，在800 o C下，通过施加临界电场，可以 在合适的限制电流密度下瞬间实现界面的强结合， 结合强度达到133 MPa。闪焊由内部缺陷反应生成 氧空位和金属镍扩散填充氧空位聚集形成的孔洞与 裂纹两个相互竞争的过程来控制，只有在合适的条 件下，孔洞和裂纹形成的速率低于金属镍的填充速 率才能获得良好的结合强度。由于氧空位在电场作 用下由正极向负极运动，当反向加载电场时，会使 连接好的3YSZ陶瓷与镍基高温合金快速脱开，因此 闪焊过程主要依赖于临界电场作用下氧化锆陶瓷中 出现的内部缺陷反应。 我们还在3YSZ陶瓷与钛合金 的闪焊连接中进一步验证了上述机理 [34] 。 如图6所示，3YSZ陶瓷与3YSZ陶瓷之间也可以 通过闪焊技术连接在一起 [35][36] [37] ， 以及3YSZ与氧化铝陶瓷 [38] 。 图6 两个3YSZ陶瓷块与夹在其中间的3YSZ陶瓷薄板闪焊 成一个整体构件的照片 Fig. 6 Picture of an integrated component flash joined from two 3YSZ blocks and a 3YSZ thin plate…”