1988 Volume 6 Issue 4 Pages 499-504
The solid-liquid interface phenomena in cemented tungsten carbide (WC-6% Co) /carbon steel (0.11%, 0.47%and 0.85%C) joints brazed with copper filler metal and the shear strength of the joints have been studied.
In copper brazing of cemented carbide to carbon steel, the carbon steel dissolves into molten copper filler metal and, simultaneously, the dissolved iron deposits from the cemented carbide as the columnar phase at a constant brazing temperature-that is, a "dissolution and deposit of base metal" takes place.
The columnar phase consists of Fe-6-11%Co-11-10%Cu-0-1%W-0.5%C alloy for the combination of 0.11%C steel; Fe-6-15%Co-9-8%Cu-0-2%W-0.5%C alloy for 0.47%C steel; Fe-7-17%Co-l0-8%Cu-0-2%W-0.9%C alloy for 0.85%C steel. The growth of the columnar phase is faster as the carbon content of the steel is smaller.
In cemented carbide/0.11%C steel joint, the shear strength of the joint increases from 346 MPa to 441 MPa when both base mtels are linked with the columnar phase.