A fuse is just a very low-valued resistor with the intention of self-destructing under specified circumstances. The "low-valued" aspect is application-dependent. It's possible to have a fuse with \$10\:\Omega\$ that would be good in one application and terrible in another.

A conventional fuse like yours will experience ohmic heating. If this becomes sufficient to cause melting, the link material may have been selected so that it constricts (pulls apart) and one more arcs form (fast blow.) This greatly increases the circuit resistance and its Ohmic heating and, in rapid progression, it consistently "fails open" and the circuit is interrupted. (As it is intended to be.)

Not all fuses are alike in the way they self-destruct. Materials are carefully selected. Those materials that rapidly constrict will be fast-blow. Other materials are more like a conventional wire and heat up gradually and eventually fail. These are slow-blow. Hopefully, all of them are well-designed for their application.

The design involves not only the selection of an appropriate conducting amalgam for the fusing wire, but other additions to modify the overall behavior (a larger, added dissipation surface over part of the fuse, for example.) It also requires extensive testing against manufacturing variability (no two are exactly alike, but all of them must behave within prescribed parameters.)

As a fuse begins to fail open, as the material changes state from a solid towards either a liquid or gas, energy that once was increasing the sensible heat will instead go into latent heat during that transformation. This is transition between the pre-arc and post-arc time periods. The Meyer integral is often used to compute the pre-arc phase.

Physicists would prefer action, as the fusing point is really measured in Joule-seconds (and Planck gave that the name action a long time ago.) There is both a melting integral and an arcing integral for a fuse. These, when summed, are called the clearing integral of the fuse. You won't usually see all those details from manufacturers, though.

The basic idea of a fuse is that you need to deliver a certain number of Joules and do so within a certain amount of time (or less) in order to guarantee the fuse opens. This is also called the all-fire specification. So, for example, you may have a fuse that gives an all-fire specification of \$500\:\text{mJ}\$ in \$50\:\text{ms}\$. You need to know details of the fuse to know if you can achieve this, of course. But note that the all-fire specification avoids details such as current, resistance, etc., as it's really about material science and the fuse structure and physical design and expected operating environment.

Most manufacturers will instead only specify the melting integral. This is often found under a table column labeled \$I^2\,t\$. The manufacturer units are wrong, but it does specify the important details. The complication is that the resistance of the fuse evolves as it opens up and specifying the units that physicists like wouldn't really be of much help to engineers. And since the action is proportional to \$I^2\,t\$, that's sufficient for all engineering purposes. Keep in mind that \$I^2\, t\$ is usually only valid under adiabatic conditions, without external heat transfer beyond what the manufacturer can normally predict. If you do something extra that provides added routes for dissipation, the fuse will behave differently.

A fuse is just a very low-valued resistor with the intention of self-destructing under specified circumstances. The "low-valued" aspect is application-dependent. It's possible to have a fuse with \$10\:\Omega\$ that would be good in one application and terrible in another.

A conventional fuse like yours will experience ohmic heating. If this becomes sufficient to cause melting, the link material may have been selected so that it constricts (pulls apart) and one or more arcs form (fast blow.) This greatly increases the circuit resistance and its Ohmic heating and, in rapid progression, it consistently "fails open" and the circuit is interrupted. (As it is intended to be.)

Not all fuses are alike in the way they self-destruct. Materials are carefully selected. Those materials that rapidly constrict will be fast-blow. Other materials are more like a conventional wire and heat up gradually and eventually fail. These are slow-blow. Hopefully, all of them are well-designed for their application.

The design involves not only the selection of an appropriate conducting amalgam for the fusing wire, but other additions to modify the overall behavior (a larger, added dissipation surface over part of the fuse, for example.) It also requires extensive testing against manufacturing variability (no two are exactly alike, but all of them must behave within prescribed parameters.)

As a fuse begins to fail open, as the material changes state from a solid towards either a liquid or gas, energy that once was increasing the sensible heat will instead go into latent heat during that transformation. This is transition between the pre-arc and post-arc time periods. The Meyer integral is often used to compute the pre-arc phase.

Physicists would prefer action, as the fusing point is really measured in Joule-seconds (and Planck gave that the name action a long time ago.) There is both a melting integral and an arcing integral for a fuse. These, when summed, are called the clearing integral of the fuse. You won't usually see all those details from manufacturers, though.

The basic idea of a fuse is that you need to deliver a certain number of Joules and do so within a certain amount of time (or less) in order to guarantee the fuse opens. This is also called the all-fire specification. So, for example, you may have a fuse that gives an all-fire specification of \$500\:\text{mJ}\$ in \$50\:\text{ms}\$. You need to know details of the fuse to know if you can achieve this, of course. But note that the all-fire specification avoids details such as current, resistance, etc., as it's really about material science and the fuse structure and physical design and expected operating environment.

Most manufacturers will instead only specify the melting integral. This is often found under a table column labeled \$I^2\,t\$. The manufacturer units are wrong, but it does specify the important details. The complication is that the resistance of the fuse evolves as it opens up and specifying the units that physicists like wouldn't really be of much help to engineers. And since the action is proportional to \$I^2\,t\$, that's sufficient for all engineering purposes. Keep in mind that \$I^2\, t\$ is usually only valid under adiabatic conditions, without external heat transfer beyond what the manufacturer can normally predict. If you do something extra that provides added routes for dissipation, the fuse will behave differently.