A novel TiB₂-based ultra-high-temperature ceramic containing 60 vol.% TiB₂, 20 vol.% TiC, and 20 vol.% SiC was fabricated by hot pressing and subsequently joined using the brazing technique. Ti-based filler was used as the brazing alloy by taking advantage of the reaction between Ti and TiB₂-TiC-SiC. The effects of the brazing temperature on the microstructure and mechanical properties of the brazed joint were investigated. The results showed that Ti in the filler reacted with the TiB₂-TiC-SiC ceramics and formed a reaction layer I that comprised TiB and TiC. The brazing seam was composed of TiB, TiC, Ti₅Si₃, Ti₂Ni, and TiNi. When the brazing temperature was increased, the reaction between TiB₂-TiC-SiC ceramics and the filler was observed to become vigorous; this led to an increase in the growth of the reaction layer I. Meanwhile, the continuous Ti₂Ni layer in the brazing seam gradually disappeared; it was replaced by TiB and Ti₅Si₃. The room temperature shear strength reached a maximum value of 168 MPa when the joint was brazed at 1040 °C for 30 min; while it was 104 and 81 MPa at test temperature of 600 °C and 800 °C, respectively. In addition, the effects of TiB whiskers on the coefficient of thermal expansion of the brazing seam and fracture of the brazed joint were discussed.

一种新颖的TiB ₂基超高温陶瓷含有60体积％的TiB ₂，20体积％的TiC，以及20体积％的SiC是通过使用钎焊技术的热压和随后加入制造。通过利用Ti和TiB ₂ -TiC-SiC之间的反应，将Ti基填料用作钎焊合金。研究了钎焊温度对钎焊接头组织和力学性能的影响。结果表明，填料中的Ti与TiB ₂ -TiC-SiC陶瓷反应并形成包含TiB和TiC的反应层I。钎焊缝由TiB，TiC，Ti ₅ Si ₃，Ti _2组成Ni和TiNi。当提高钎焊温度时，观察到TiB ₂ -TiC-SiC陶瓷与填充剂之间的反应剧烈。同时，钎焊缝中连续的Ti ₂ Ni层逐渐消失。用TiB和Ti ₅ Si ₃代替。当接头在1040°C钎焊30分钟时，室温剪切强度达到168 MPa的最大值。试验温度为600℃和800℃时分别为104和81 MPa。此外，还讨论了TiB晶须对钎焊缝的热膨胀系数和钎焊接头断裂的影响。