Fusibility

The fusibility of a material refers to the ease at which the material can be fused together, or to the temperature or amount of heat required to melt a material. Materials such as solder require a relatively low melting point so that when heat is applied to a joint, the solder will melt before the materials being soldered together melt, i.e. high fusibility. On the other hand, firebricks used for furnace linings only melt at very high temperatures (and then they retract, or decompose, or become fracture-prone) and so have low fusibility. Perhaps refractory materials often have low fusibility.