The invention relates to a method for
brazing dissimilar materials, in particular to a method for
brazing dissimilar materials through assistance of a carbon
nano tube sponge middle layer and aims atsolving the problem that an existing
metal material and dissimilar material brazed joint is low in strength. The method comprises the following steps that carbon nano tubes are mixed with a strong acid solution for ultrasonic cleaning, the obtained solution is dispersed into deionized water, suction
filtration is conducted, an obtained
filter cake is ultrasonically dispersed into absolute ethyl
alcohol, centrifuging is conducted, and a supernatant is obtained; then suction
filtration and
drying are conducted, and finally
brazing is conducted on the dissimilar materials. Or the carbon nano tubes are mixed with the strong acid solution for ultrasonic cleaning, then the obtained solution is dispersed into the deionized water, suction
filtration is conducted, the
filter cake is ultrasonicallydispersed into the absolute ethyl
alcohol, centrifuging is conducted, and the supernatant is obtained; and brazing
filler metal powder is added into the supernatant, then suction filtration and dryingare conducted, and finally brazing is conducted on the dissimilar materials. The preparation method of carbon
nano tube sponge is simple and low in cost, agglomeration of the carbon nano tubes in thebrazing process can be avoided, and interface structure regulation and control, brazing seam
performance enhancement, joint
residual stress relief and joint strength improvement are facilitated. Themethod is suitable for brazing the dissimilar materials.