Low melting point alloys refer to fusible alloys with a melting point below 232°C (the melting point of Sn), typically composed of low melting point metallic elements such as Bi, Sn, Pb, and Cd. These alloys are widely used as soldering materials, as well as thermal-sensitive components like fuses and fusible links in electrical, steam, firefighting, and fire alarm systems. They represent a class of novel low melting point alloy materials with significant development potential.

Low melting point tin-bismuth mold alloys are used to manufacture cold stamping dies for thin sheets, capable of pressing copper, aluminum, steel, stainless steel, and other sheet metals, with steel sheet thickness up to a certain limit. They are applied in the stretching, bending, and forming of thin sheets. Using low melting point alloy molds eliminates the need for mold steel, simplifies and speeds up mold formation, reduces mold costs, allows for rapid updates, requires no adjustments or machining, and enables the alloy to be remelted and reused after mold use. Due to the rapid mold formation process, storage space for molds can be significantly reduced.

Low melting point tin-bismuth alloy molds utilize non-ferrous metal alloys with relatively low melting points as casting materials. Based on a master pattern, the mold is cast and formed within a melting box. In the late 20th century, low melting point tin-bismuth alloy molds found applications, particularly in the field of deep drawing molds for automotive panels, where their advantages are more pronounced.

Characteristics of low melting point tin-bismuth alloys: Stamping molds feature the simultaneous formation of punches and dies through casting, with uniform clearance between them after casting, requiring no adjustments during use. Molds can be cast directly on a press machine and used immediately after casting. The casting alloy material can be repeatedly remelted and cast or repurposed for other molds. It is anticipated that with economic development, tin-bismuth alloys will enjoy broader application prospects.