Controllable distribution of reinforcements for reducing the strain energy in dissimilar ceramic/metal joints

摘要

A novel design of a multi-layered joint architecture, characterized by the controllable spatial distribution of ceramic reinforcements, was obtained, when brazing ZrB2-SiC ceramics and Ti-6Al-4 V reinforced by TiB whiskers with AgCu filler. To induce SiC reinforcements to cluster together, within the center of the filler and especially away from the ZrB2-SiC, SiC was added into joint, in the form of a SiC interlayer featuring a 3D-bridged network structure with continuous micro-channels infiltrated by capillary force by liquid filler during brazing. Different SiC particles were connected together, by micro-bridges being not destroyed during brazing. The layer rich in SiC could reduce thermal expansion mismatch between different substrates, the AgCu next to the ZrB2-SiC could relax the strain energy by high plastic deformation. Compared to joint brazed with single AgCu, joint strain energy decreased from 10.8 x 10(-6) J to 8.6 x 10(-6) J, accordingly joint shear strength increased from similar to 5.4 MPa to similar to 41.2 MPa.