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

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。

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

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 achieve the TLP bonding of SiCp/Al 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.