Precipitation hardening and recrystallization of Al-0.3wt.% Zr alloys of various grades

Precipitation hardening in dilute Al–Zr alloys

The aim of this study was to investigate the effect of solute content (hipoperitectic Al–0.22 wt.%Zr and hiperperitectic Al–0.32 wt.%Zr) on the precipitation hardening and microstructural evolution of dilute Al–Zr alloys isothermally aged. The materials were conventionally cast in a muffle furnace, solidified in a water-cooled Cu mold and subsequently heat-treated at the temperature of 650 K (3...

Precipitation Hardening of Al–Si–Mg Alloys

Precipitation evolution in Al–Zr and Al–Zr–Ti alloys during aging at 450–600 C

The transformation of Al3Zr (L12) and Al3(Zr1 xTix) (L12) precipitates to their respective equilibrium D023 structures is investigated in conventionally solidified Al–0.1Zr and Al–0.1Zr–0.1Ti (at.%) alloys aged isothermally at 500 C or aged isochronally in the range 300– 600 C. Titanium additions delay neither coarsening of the metastable L12 precipitates nor their transformation to the D023 st...

Precipitation Hardening of Metal Alloys

Precipitation hardening, or age hardening, provides one of the most widely used mechanisms for the strengthening of metal alloys. The fundamental understanding and basis for this technique was established in early work at the U. S. Bureau of Standards on an alloy known as Duralumin [1,2]. Duralumin is an aluminum alloy containing copper and magnesium with small amounts of iron and silicon. In a...

Nucleation and Precipitation Strengthening in Dilute Al-Ti and Al-Zr Alloys

Two conventionally solidified Al-0.2Ti alloys (with 0.18 and 0.22 at. pct Ti) exhibit no hardening after aging up to 3200 hours at 375 C or 425 C. This is due to the absence of Al3Ti precipitation, as confirmed by electron microscopy and electrical conductivity measurements. By contrast, an Al-0.2Zr alloy (with 0.19 at. pct Zr) displays strong age hardening at both temperatures due to precipita...