Composite Precipitates in Al–Li–Ti Alloys

X-ray Analysis of Precipitates Formed in Copper-base Alloys

The formation and growth process of precipitates in Cu-Ni-Si alloys during aging were investigated by anomalous small angle scattering (ASAXS) and X-ray absorption fine structure (XAFS). ä-Ni2Si precipitates with wide nanometer size distribution were formed in the Cu-Ni-Si alloys after a long aging time of 10 s. However, the addition of a small amount of Fe appears to reduce the wide-size distr...

Ferritic Alloys with Extreme Creep Resistance via Coherent Hierarchical Precipitates

There have been numerous efforts to develop creep-resistant materials strengthened by incoherent particles at high temperatures and stresses in response to future energy needs for steam turbines in thermal-power plants. However, the microstructural instability of the incoherent-particle-strengthened ferritic steels limits their application to temperatures below 900 K. Here, we report a novel fe...

ATOM PROBE CHARACTERIZATION OF PREPRECIPITATE CLUSTERS AND PRECIPITATES IN Al-Mg-Si(-Cu) ALLOYS

Pre-precipitation clustering and chemical nature of the metastable precipitates in aged Al-Mg-Si(-Cu) alloys have been investigated by atom probe field ion microscopy (APFIM) and transmission electron microscopy (TEM) for better understanding of the two-step aging behavior and the effect of excess Si. After a prolonged natural aging, co-clusters of Mg and Si atoms are observed in addition to se...

Structure change of δ’ precipitates during heating at a constant rate in Al-Li binary alloys

Grain Boundary Character Dependence on Nucleation of Discontinuous Precipitates in Cu-Ti Alloys

The dependence of the grain boundary character distribution for a Cu-4 at. % Ti polycrystal alloy (average grain size: 100 µm) on the nucleation of cellular discontinuous precipitates was systematically investigated. In an alloy over-aged at 723 K, cellular discontinuous precipitates consisted of a terminal Cu solid solution and a stable β-Cu₄Ti lamellae nucleated at grain boundaries. Electron ...