Six-element medium-entropy alloy brazing filler metal and preparation method and brazing method thereof

The invention relates to the technical field of brazing, and provides Zr-Ti-Hf-Ni-Cu-Co six-element medium-entropy alloy brazing filler metal used for pure titanium and titanium alloy brazing and a using method of the Zr-Ti-Hf-Ni-Cu-Co six-element medium-entropy alloy brazing filler metal. The invention provides Zr-Ti-Hf-Ni-Cu-Co six-element medium-entropy alloy brazing filler metal. The brazing filler metal comprises the following components in percentage by weight: 9.5-13.9% of Ti, 0.5-1.5% of Hf, 0.5-1.5% of Ni, 0.5-1.5% of Cu and the balance of Zr. Ni: 5.5 to 9.5%; 5.0 to 9.5 percent of Cu; 2.0 to 8.5 parts of Co; 0 to 2.0% of Hf; zr: the balance. The brazing filler metal has the following technical effects that the liquidus temperature of the brazing filler metal ranges from 769 DEG C to 782 DEG C, the brazing filler metal is easily formed into amorphous brazing filler metal alloy, and the shear strength of a pure titanium-titanium alloy connector obtained after heat preservation is conducted for 10 minu