TEM Analysis of Grain Boundary Precipitate-Free-Zones (PFZs) in AlCuSiGe Alloy,

TOLLEY, ALFREDO JUAN; DAVID MITLIN,; VELIMIR RADMILOVIC,; ULRICH DAHMEN,

Phoenix

Congreso; Microscopy and Microanalysis 2004; 2004

Microscopy Society of America

AlCuSiGe based alloys have potential commercial application due to their combination ofreasonably high strength, quick aging response and excellent high temperature stability. In previouswork [1-3], we have shown these favorable properties to be a result of a dense distribution ofthermally stable θ’ precipitates. One issue not addressed in previous studies of the AlCuSiGemicrostructure is the precipitate-free zone (PFZ) present adjacent to the grain boundaries. Becausethe PFZs can cause catastrophic failure of otherwise strong materials, their control is a veryimportant consideration in the development of any commercially viable alloy. The goal of this workis to investigate the PFZs in Al-2.5Cu-0.5Si-0.5Ge (at.%) aged at 190°C.