Eutectic system
An alloy composition where the melting point reaches a minimum and the melt solidifies isothermally at the lowest temperature.
A eutectic is an alloy composition that has a single, sharply defined melting point. In welding, this means: the whole melt becomes liquid at once and solidifies as a whole again – there is no wide melting range where you can still correct something. This makes things tricky. If you get too hot or don't manage the heat cleanly, the pool can quickly tip over and you get structural defects. You have to keep the heat input steady and even so nothing overheats or cools too fast. In practice, this means: preheat properly, run constant energy, and don't apply too much at once. Watch the weld pool closely – if it starts to flow, the temperature is at its limit.