Initial stages of wetting of alumina by reactive CuAgTi alloys

The initial stages of spreading of CuAgTi alloys on alumina are investigated by the dispensed drop technique in a high vacuum. The experimental results of spreading rate are compared with the predictions of two different models and the elementary processes controlling the spreading kinetics are determined.

► CuAgTi alloys wet alumina in three different kinetic stages.
► The wetting rate is limited successively by the friction at the triple line, diffusion and reaction.
► Wetting in real systems is expected to be a multistage process.