The reactive wetting and interfacial characteristics of the Sn-2Ti active solder were experimentally investigated on sintered polycrystalline diamond (PCD) substrates containing 8-18 wt.%Co binders. The initial spreading temperature of Sn-2Ti on PCD was determined by the continuously elevating temperatures wetting experiment. The Sn-2Ti started to spread on PCD at 500-630 degrees C. The higher the cobalt content, the lower the initial spreading temperature. Meanwhile, the spreading kinetics analysis through isothermal wetting experiment indicated the spreading process of Sn-2Ti on PCD can be well described by the dassic chemical reaction-controlled model at 650-900 degrees C. Both rod-like TiC carbide and faceted CoSnTi intermetallics (IMCs) were observed at the wetting triple line, with the formation morphologies strongly depending on wetting temperatures. The results obtained in this work are believed to be of importance for the optimization of brazing technique for sintered PCD, and hence the development of PCD diamond machining tools with minimized thermal damages. (C) 2020 Published by Elsevier B.V.