What typically encapsulates the conductive link in a fuse?

A fuse operates by connecting its conductive link to an encapsulating material that helps to extinguish any arc formed when the fuse blows. Silica sand is particularly effective for this purpose because it has high thermal resistance and can absorb heat generated during the interruption of the circuit. When the fuse element melts, the resulting arc creates intense heat, and the silica sand helps to cool and quench this arc, preventing it from causing further damage or posing a hazard.

While oil, plastic, and metal casing can serve other functions in electrical components or devices, they do not provide the same level of efficacy in interrupting electrical arcing within a fuse as silica sand does. Oil can potentially facilitate cooling but may not effectively quench arcs in the same manner. Plastic is commonly used for insulation and structural support but lacks the necessary properties to manage an electrical fault like that of silica sand. Metal casing might protect the fuse and provide a grounding path, but it does not have the appropriate capacity to handle the thermal effects of an arc as effectively as the encapsulation by silica sand does.