The nonwettability behaviour of solid substrates in contact with chemical active reach Ti-, Zr- and Hf-liquid alloys

Searching for solid materials that are not wetted by Ti, Zr or Hf alloys and are stable in contact with them is an important task from both the scientific and the practical points of view. The metal alloys for investigation were as follows: Cu-Ti, Cu-Zr, Cu-Hf, Cu-Sn-Ti, Cu-Ga-Ti, Ni-Cu, Ni-Zr and Ni-Hf. The contact angles, adhesion of solidified alloys and some parameters of interface interaction (saturation of liquid metal by components of solids) were estimated. The contact angle values for the investigated alloys at high concentration of active metals on CaF2, MgF2 and BaF2 surfaces wee 108-124 degrees at 1150-1250 C. Under the same conditions contact angles of these alloys on alumina, zircon or graphite were 0 degrees. Full melt spreading was observed. Ti, Zr, and Hf react with solid fluorides giving chemical compounds of type TiFx. The properties of these substances are presented. 11 refs.