Precipitation Hardening in (α+β) and Lead-Tin Brasses

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...

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

Conventional Tin-Lead and RoHS-Compliant Lead-Free Components

1 While lead-frame and wire-bond packages can be provided as eutectic or lead-free, currently Altera flip-chip packages are RoHS compliant. We use Exemption #15 for the first Level Connections between the flip-chip die to the substrate (RoHS Exemption #15: Lead in solders to complete a viable electrical connection between the semiconductor die and the carrier within the integrated circuit flip-...

Photorefraction in lead tin-fluorophosphate glasses.

Permanent grating patterns have been written directly in lead-tin-fluorophosphate glasses by use of UV radiation. The effect of photorefraction is studied in different tin-fluorophosphate compositions. Recorded gratings are found to be volume rather than surface elements. The induced index changes are comparable with those seen in GeO(2)- SiO(2) glasses.