SURFACE TENSION OF LIQUID Ni-P AND Ni-Zr-P ALLOYS AND THEIR WETTABILITY ONTO ALUMINA

The surface tension of liquid Ni-P and Ni-Zr-P alloys and their wettabilityonto Al_2O_3 substrates were measured by the sessile drop method. The distributionof P along the depth beneath the surface of the alloy was determined by AES.Results show that the P is a surface-active element in liquid Ni and the surfacetension of liquid Ni-base alloy is obviously decreased by the increasing of P con-tained when a small amount of Zr existed. The maximum adsorption value ofP on the liquid Ni surface is rather close to the measured value by AES. Thewettability of Iiquid Ni-P onto Al_2O_3 is concerned with the P content in the all-oys and decreases as less Zr contained in them. The apparent shearing strengthof the Ni-base alloys against Al_2O_3 substrate was also evaluated.