Abstract
C103 and Ti–6Al–4V alloys jointed with Ti–15Cu–15Ni (wt.%) commercial brazing foil by vacuum-furnace brazing were investigated. Our previous study [I.-T. Hong, C.-H. Koo, Mater. Sci. Eng. A 398 (2005) 113] demonstrated that Ti–15Cu–15Ni (wt.%) filler-metal can successfully braze C103 and Ti–6Al–4V alloys, and identified all phases in the joint interface. The relationship between the microstructure and the joint performance, and the solidification process of the liquid filler-metal in the joint interface were also studied in detail. Therefore, the current study mainly focuses on how to further improve the microstructure and mechanical properties of the C103/TiCuNi/Ti–6Al–4V joint via post-brazing treatments or using various joint designs, such as overlap-length of joints, surface roughness of the parent-metals and joint clearance. Moreover, the high temperature shear strength of the C103/TiCuNi/Ti–6Al–4V joint was investigated to evaluate its limit service temperature. The experimental results reveal that the fracture load of joint reaches a maximum of 31,076N, and the joint fractures in C103 parent-metal when the overlap-length of the joint increases to 3.5 times the thickness of the parent-metal (3.5T, 7mm). However, the joint shear strength decreases with the overlap-length of the joint because of the non-uniform stress distribution in the lap joint during shear test. Post-brazing treatment at 880°C for 4h increases the shear strength of the joint brazed at 960°C for 15min by 16%, from 352 to 411MPa. However, prolonging the post-brazing time to 6h reduces the shear strength of the joint to 299MPa. A comparison with the coarse Widmanstätten structure reveals that the presence of some fine Widmanstätten structure that forms in the joint interface during post-brazing treatment does not seem to deteriorate the joint shear strength. Moreover, the shear strength of joints decreases as the surface roughness of parent-metals decreases or the joint clearance increases. The results of the high temperature shear test reveal that the shear strength of the C103/TiCuNi/Ti–6Al–4V joint maintains at around 300MPa at the test temperature below 600°C. However, as the test temperature exceeds 600°C, the shear strength of C103/TiCuNi/Ti–6Al–4V joint declines greatly.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
