The invention relates to the field of heat conduction materials and provides low-melting-point
alloy. The low-melting-point
alloy comprises, by
mass, 47.0-50.8% of
indium, 29.5-32.3% of
bismuth, 13.5-16.3% of
tin and 0.67-10% of
gallium. A preparation method of the low-melting-point
alloy comprises the steps that A, all the constituents are weighed according to requirements; B, the
furnace temperature is increased to 350 DEG C, the
bismuth and the
tin are placed into a
ceramic crucible, the
ceramic crucible is placed into a
smelting furnace to be heated, after the
bismuth and the
tin are melted,
surface oxide is removed, and stirring is conducted; C, the
furnace temperature is adjusted to 200 DEG C, the
indium is added, and after the
indium is completely melted, surface slagging-off and stirring are conducted; D, the
furnace temperature is adjusted to 100 DEG C, the
gallium is added, and slagging-off and standing are conducted after stirring; and E, the
crucible is taken out, the alloy is poured into a mold, and cooling is conducted. The
melting point of the low-melting-point alloy is 40-60 DEG C, the low-melting-point alloy is used for low-junction-temperature occasions in a phase-change mode, and the application space of
liquid metal thermal interface materials is enlarged; harmful elements such as lead and
cadmium are not contained in the low-melting-point alloy product, and environment protection is facilitated. The preparation method is simple in technological requirement, and the whole process can be conducted in the atmospheric environment.