钛合金与铝基复合材料钎焊接头组织及力学性能

Microstructure and mechanical properties of brazed joints between titanium alloy and aluminum matrix composites

通过一种超声辅助钎焊连接方法,采用Zn基钎料对TC4钛合金和55%Si Cp/Al复合材料进行了钎焊连接。通过扫描电镜、能谱议及电子万能试验机对钎焊接头的微观组织、界面成分及接头的剪切强度进行了分析研究。结果表明,超声辅助钎焊连接方法可以有效实现钛合金与55%Si Cp/Al复合材料的冶金连接。接头中复合材料侧界面氧化膜完全消失,并且基体中的小尺寸Si C颗粒向钎缝中大量迁移。而在钛合金侧界面处只生成了一种金属间化合物Ti Al3,平均厚度为2~4μm。在420℃焊接时接头的最高剪切强度可达到167 MPa,其试样接头断裂于金属间化合物Ti Al3和55%Si Cp/Al复合材料的界面区附近。

Ultrasonic-assisted brazing of two dissimilar materials,55% Si Cp/ Al composite and TC4 titanium alloy,using Zn-based filler metal was investigated. The microstructure and constituent phases of the joints were examined by scanning electron microscopy（ SEM）and energy dispersive spectrometer（ EDS） analysis and the shear strength of the joints was tested. The results show that metallurgical bond is obtained between titanium alloy and 55% Si Cp/ Al composite by the ultrasonic-assisted brazing. The oxide films disappear entirely in the composite side of the joint. A number of smaller Si C particles migrate into the brazing seam by the ultrasonic wave. Only Ti Al3phase（ a thickness of about 2-4 μm） is formed in the interfacial area of the titanium alloy side of the joint. The maximum shear strength of 167 MPa has been attained for the bond made at 420 ℃. It is found that the fracture occurs at the interface region between Ti Al3 phase and 55% Si Cp/ Al composite in the joint.