Wettability of Ni–V, Co–V, and Ni–Cr–V system brazing alloys on Si3N4 ceramic and interfacial reactions

In the present paper, six V-active brazes were designed. The wetting behavior of Ni–V, Co–V and Ni–Cr–V alloys on Si3N4 was studied by the sessile drop method. The results show that, under the heating condition of 1553 K/120 min, the Ni–V alloys with the V content of no higher than 25 wt.% did not wet Si3N4, whereas, the Ni–V alloys with the V content of no lower than 34.5 wt.% exhibit good wettability. Though the spreading of the Ni–V, Co–V and Ni–Cr–V brazing alloys on the Si3N4 was slow, intensive interfacial reactions occurred, and according to the results of XRD analysis, compounds of V3Ni2Si, V6Si5 and VN were formed at the interface of Si3N4/Ni–V alloy. The corresponding interfacial reactions were also discussed.