Effect of Ti-Al content on microstructure and mechanical properties of Cf/Al and TiAl joint by laser ignited self-propagating high-temperature synthesis
(State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China)
Abstract: Cf/Al composites and TiAl alloys were joined by laser ignited self-propagating high-temperature synthesis (SHS) with Ni-Al-Ti interlayer. The effect of Ti-Al content on interfacial microstructure and mechanical properties of the joints was investigated. Localized melt of the substrates occurred in the joints. γ-Ni0.35Al0.30Ti0.35, NiAl3 and Ni2Al3 reaction layers formed adjacent to the substrates. Joint flaws, such as pores and cracks, made the joint density decrease and worked as the fracture source, which led to the sharp decline of joint strength. Additive Ti-Al increased joint density and strengthened the interlayer adhesion to Cf/Al. The joint flaws could be controlled by changing the Ti-Al content. When the Ti-Al content was 0.1, the joint was free of cracks with high density and reached the maximum shear strength of 24.12 MPa.
Key words: Cf/Al composite; TiAl alloys; joint; self-propagating high-temperature synthesis; interlayer; Ti-Al content