Laser-induced exothermic bonding of carbon fiber/Al composites and TiAl alloys

Publication date: 15 July 2017
Source:Materials & Design, Volume 126
Author(s): Guangjie Feng, Zhuoran Li, Rohit J. Jacob, Yong Yang, Yu Wang, Zhi Zhou, Dusan P. Sekulic, Michael R. Zachariah
In this paper, a highly-efficient method for bonding Carbon Fiber (Cf)/Al composites and TiAl alloys was developed by means of laser-induced exothermic reaction of a Ni-Al-Ti interlayer. To examine the interlayer exothermic performance, the adiabatic temperature was calculated and the reaction temperatures were measured. Based on SEM, XRD and TEM, the interfacial reactions between carbon fiber and interlayer products were investigated. Results show that the addition of Ti enhanced the interfacial reactions between carbon fibers and interlayer products. The resulting formation of a 300–400nm thin Ti-C layer at the NiAl3/carbon fiber interface was identified as a key player in improving the joining quality on the Cf/Al side. The typical interfacial structure of the joint is (Cf/Al)/Ti-C/NiAl3/Ni2Al3/(NiAl+Al3NiTi2)/Al3NiTi2/TiAl. The joint formation mechanism was discussed. In addition, the effect of Ti content on the microstructure and mechanical properties of joints were investigated in detail. The optimum value of Ti content was found to be 5wt.%, leading to a defect-free joint and a maximum shear strength of 45.8MPa.

Graphical abstract

http://ift.tt/2oM0vz1