The invention discloses a method for preparing a high-melting-point
metal ternary
diffusion couple. The method is mainly used for preparing the
diffusion couple composed of three kinds of high-melting-point
metal. The method comprises the following steps: paving a B
metal block or sheet with the lowest
melting point in three kinds of high-melting-point metal above an A metal block, then putting A-B metal into a tubular furnace protected by
argon, heating to be above the
melting point of the B metal, melting the B metal to form metallurgical bonding with the A, and performing
diffusion annealing to form an A-B diffusion couple; and then
coating the C
metal sheet at the interface of the A-B diffusion couple, fixing the C
metal sheet by using a clamp, and performing diffusion annealing to prepare the A-B / C ternary diffusion couple. The method is simple, the amount of needed metal is small, the preparation process is easy to control, diffusion couple combination is flexible and controllable, the effect is excellent, and the success rate is high. The method is suitable for preparation of metal material diffusion couples, especially for preparation of
precious metal and high-temperature
alloy material diffusion couples, and the prepared diffusion couples can be used for research of phase diagrams, diffusion
kinetics and
thermodynamics.