脉冲电流辅助粉末夹层TLP连接SiC_p/Al接头微观组织和力学性能

Pulse Current Assisted TLP Bonding of SiC_P/Al Composites Sheet Using Powders Interlayer

研究脉冲电流辅助瞬间液相(Transient Liquid Phase,TLP)扩散连接技术,采用粉末中间层,利用低压高强脉冲电流通过铝基复合材料搭接面与中间层,从而实现对SiC_p/2024Al复合材料板材的TLP扩散连接。分析不同工艺参数下连接试样的微观组织和力学性能,探索脉冲电流对铝基复合材料连接的影响机理。结果表明:采用真空压强为1×10^(-3)Pa,平均电流密度115 A/mm^2,连接预紧压力为0.5 MPa,连接时间60 min条件下,连接接头形成了良好的冶金连接界面,无缺陷产生;通过对连接接头微观组织观察发现,在脉冲电流作用下,接头原位生成弥散的高强度高硬度金属间化合物增强相,有效地提高了接头的力学性能。

The powders interlayer was applied for transient liquid phase （TLP） bonding of SiCp/Al composites using pulse current heating. Pulse current got though the joint with powder interlayer and generated the effect of Joule heat and spark plasma sintering to a-chieve the TLP bonding of SiCp/A1 composites sheet. The results show that there is the good TLP bonded joint without defects under the conditions of vacuum： 1.39 × 103 Pa; Pulse current density： 115 A/mm2 ; holding time： 15 - 60 min; original pressure： 0. 5 MPa. The results reveal the dense joint without pores composed of the Al-based solid solution, pure Ti zone, Al2Cu, and Al3Ti intermetallic phase. Furthermore, the thermal and isothermal effects of pulse current on in situ synthesis of TLP bonded joints of SiCp/Al composites using mixed Al-Cu-Ti powder interlayer are analyzed and discussed. According to microstructure of joint, pulse current promote to in situ form the intermetallic compound, which can provide higher mechanical properties of joint.