The isotherm wetting and spreading behaviors of the molten Ag-Cu-Xwt.%Ti filler metals with 0 wt.%, 1.5 wt.%, 3 wt.% and 4.5 wt.% Ti on SiC ceramic substrates were investigated at 1050 K in a flowing Ar atmosphere using a modified sessile drop method. The wettability improves gradually with the increase of Ti content because that the interfacial chemical reaction caused by element Ti diffusing into the liquid filler metal, which can not only lead to the free energy releasing (Delta Gr) but also cause the interface energy changing (Delta delta r). The reactive wetting processing can be divided into four stages, which are Delta Gr limited spreading stage (stage I), Delta delta r-limited spreading stage (stage II), stabilization stage (stage III) and contraction stage (stage IV), in which, the free energy releasing plays a dominant role in determining the spreading in stage I while the interface energy changing is more important in stage II. (C) 2017 Elsevier B.V. All rights reserved.