Preparation and Welding Properties of Amorphous Ni-Mo-P Filler Metal

The Ni78Mo14P8 amorphous alloy filler metal ribbon was prepared by single roller rapid solidification. The phase of filler metal was investigated by XRD, and the melting behaviour was investigated by DSC. The amorphous ribbon was used in transient liquid phase bonding between stainless steel and 20 carbon steel at 975, 1 000, 1 025, and 1 050 ℃. The shear strength and microstructure of the soldered joint was analyzed. The results show that the phase of Ni-Mo-P filler metal was single amorphous, the reduced glass transition temperature(trg) of Ni78Mo14P8 amorphous alloy was 0.54, and the supercooled liquid range (Δtx) was 41 ℃, indicating good amorphous formation ability. As brazing temperature increased, the shear strength of the brazed joint and the micro-hardness of the solder area also increased gradually. The microstructure of solder seam was FeNi solid solution phase and eutectic organization consisting of Mo2Ni6P3, Ni3P and Ni2P.