高氮钢/氧化铝陶瓷异质钎焊界面组织与力学性能分析

Interfacial Microstructure and Mechanical Properties of High-Nitrogen Steel/Alumina Ceramic Heterogeneous Brazed Joints

摘要:

为实现热电器件领域高氮钢热沉基板与氧化铝陶瓷异质接头的可靠连接，采用AgCuTi钎料对P580高氮钢与氧化铝陶瓷进行真空钎焊，系统分析钎焊温度对接头界面组织与力学性能的影响规律。研究表明，在910 ℃、10 min工艺下获得最佳接头，接头剪切强度最高达53.74 MPa，其界面结构为Al2O3/Cu3Ti3O/Ag(s,s)+Cu(s,s)+TiCu/TiN/高氮钢，陶瓷侧形成连续致密的Cu3Ti3O反应层，高氮钢侧生成TiN化合物。此时断裂发生于陶瓷近钎缝区，温度过高或过低均导致反应层不连续或破碎，降低接头强度。Ag与Cu固溶体具有良好的塑性，有助于缓解残余应力，而Cu3Ti3O反应层的厚度与连续性对界面应力状态及接头性能具有关键影响。本研究为高氮钢与氧化铝陶瓷功能性连接提供了一种高可靠钎焊工艺方案。

Abstract:

To investigate a reliable joining method for heterogeneous joints between high-nitrogen steel and alumina ceramic, vacuum brazing of P580 high-nitrogen steel and alumina ceramic was carried out using AgCuTi filler metal. The influence of brazing temperature on the interfacial microstructure and mechanical properties of the joint was systematically analyzed. The results show that the optimal joint was obtained under the process parameter of 910 °C/10 min. Its interfacial structure was Al2O3/Cu3Ti3O/Ag(s,s)+Cu(s,s)+TiCu/TiN/high-nitrogen steel. A continuous and dense Cu3Ti3O reaction layer formed on the ceramic side, while TiN compounds were generated on the high nitrogen steel side. The maximum shear strength of the joint reached 53.74 MPa, with fracture occurring in the ceramic near the brazed seam. Excessively high or low temperatures led to discontinuous or fragmented reaction layers, thereby reducing joint strength. The Ag and Cu solid solutions exhibited good plasticity, which helped alleviate residual stress, while the thickness and continuity of the Cu3Ti3O reaction layer played a key role in the interfacial stress state and joint performance. This study provides a reliable brazing process solution for the heterogeneous joining of high-nitrogen steel and alumina ceramic.