Open AccessThe Microstructure and Shear Strength of SiC Joints Brazed with SiC Particle Reinforced Si-24Ti Alloy
Author(s) -
Zhen Li,
Qun Wen,
Zhihong Zhong,
Yucheng Wu
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/678/1/012050
Subject(s) - brazing , microstructure , materials science , alloy , shear strength (soil) , composite material , scanning electron microscope , joint (building) , metallurgy , ceramic , structural engineering , environmental science , soil science , engineering , soil water
To refine the microstructure and increase the joint strength of SiC ceramic brazed with Si-24Ti (wt.%), carbon nanotubes (CNT) were added into Si-24Ti brazing alloy to form SiC particles in the braze zone. The effect of the amount of CNT in the brazing alloy on the microstructure and shear strength of joints was investigated. The microstructure and element distribution of the joint was studied by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS). The results indicated that the addition of the proper amount (1-3 wt.%) of CNT could refine the microstructure of joints and achieve high-quality SiC joints. The shear strength of the joint brazed with 3 wt.% CNT addition reached the maximum value of 108 MPa, which was 21.3% higher than that of without CNT (89 MPa). However, when the amount of CNT increased to 5 wt.%, the shear strength of joint decreased to 55 MPa, due to the formation of cavity in the joint. The strengthening mechanism of in-situ formed SiC particle in the composite brazing alloy was evaluated.