Effect of Various Carbides on the Wettability in Ni/Ti（C,N） System
摘要
The wettability in Ni / Ti ( C, N) systems with various carbides additions was investigated by the sessile drop technique. The substrates prepared by HP at 2073 K for lh before and after wetting were characterized by XRD. The microstructure at metal/ceramics interfaces was observed via SEM in a back scattered mode. Furthermore, an X-ray energy-dispersive spectrometer (EDS) attached to SEM was used to study the element diffusion in interracial regions. The results reveal that reactive wetting takes place in the system in high temperature wetting procedure, which is controlled by diffusion and dissolution mechanism. Results also show that the contact angles decrease with various carbides aditions, including WC, Mo2 C, TaC, NbC and VC, and decrease continuously with the increasing of additions. The order of the contact angles in Ni/Ti(C,N) systems with 10 wt% carbides additions is Mo2 C ＜ TaC ＜ WC ＜ VC ＜ NbC. The enhancement of the wettability is due to an alloying procedure during high temperature wetting when metallic atoms diffuse into Ni phase, which decreases the interfacial energy of Ni/Ti(C,N) systems.