Self-propagating synthesis joining of Cf/Al composites and TC4 alloy using AgCu filler with Ni-Al-Zr interlayer

The successful joining of carbon fiber-reinforced aluminum matrix (C-f/Al) composites and TC4 alloy can produce composite structure and meet the demands of lightweight in aerospace field. Up to now, few experimental researches have been reported on the joining of C-f/Al composites and TC4 alloy. In this study, the AgCu foils and Ni-Al-Zr compact were designed for the self-propagating high-temperature synthesis joining of these two materials. Cf/Al composites were joined with a reactive Ti plated on its joining surface. The typical microstructure of TC4/(AgCu/Ni-Al-Zr/AgCu)/Ti/C-f/Al joint was analyzed, and the effects of joining condition on microstructural evolution of the SHS joint were investigated. A thin reaction layer of Ni-Al-Ti intermetallic compounds was formed adjacent to the TC4 alloy. As a result, AgCu foils could reduce the effect of reaction heat on the substrates and improve the joint shear strength. When the thickness of AgCu foils reaches 150 mu m, the Ni-Al-Zr interlayer mainly acts as auxiliary heat source. High joining pressure caused the active elements to diffuse into C-f/Al composites and weakened the shear strength of the joint. Finally, the joint shear strength could reach 36.4 MPa when the AgCu foils were 50 mu m and the joining pressure was 2 MPa. Graphic abstract

Automated summary

This study successfully joined C-f/Al composites with TC4 alloy using AgCu foils and Ni-Al-Zr compact for self-propagating high-temperature synthesis. The research showed that different joining conditions had significant effects on the microstructural evolution and shear strength of the joints.