The invention discloses a TiAl-based
alloy coating resistant to contact
corrosion and a preparation method of the TiAl-based
alloy coating. The
coating is composed of the following elements including, by atom percentage, 44-47at% of Al, 2-4at% of Nb, 4-10at% of V, 0-2.5at% of Cr, 0-0.5at% of B and the balance Ti. According to the coating, intermediate
alloy AlNb, AlV and AlCr, TiB2, Al particles and high-purity
sponge Ti are mixed and then are prepared into spraying
powder; and then the spraying
powder is sprayed onto the surface of an aluminum alloy base through a low-temperature supersonic spraying technology. The
bonding strength of the coating can reach 30 MPa or above, after the coating is prepared on the surface of an aluminum alloy, the
electrode potential of the surface of the aluminum alloy can be improved, the self-
corrosion current can be reduced, the contact
corrosion sensitivity between the aluminum alloy and a
titanium alloy can be reduced, and therefore the aluminum alloy can make direct contact with the
titanium alloy for use, and the contact corrosion preventing requirement of aluminum alloy /
titanium alloy
dissimilar metal is met.