Scientists have long understood that heating a metal softens it. But a new study shows that, counterintuitively, heat strengthens pure metal in extreme conditions. Findings could lead to better designed metals for applications in extreme conditions, including outer space.
No, not necessarily. Classically, heating ferrous materials softened them, and pure metals were inferior to alloys like brass, bronze, pewter, and of course steel.
The article gives this background better than I can. You should read it.