A new insight on the diffusion growth mechanism of intermetallic compounds in Al-Er system

A new insight on the diffusion growth mechanism of intermetallic compounds in Al-Er system

Blog Article

The diffusion growth of intermetallic compounds in Al-Er alloys are closely related to the properties of the alloys.The current work aims at explaining the dominance of Al3Er in the Al-Er alloys precipitation phases and the interface thin layer phenomenon by diffusion couple technique, estimating the parabolic growth constant and diffusion activation energy of intermetallic compound in Al-Er diffusion couples to provide theoretical guidance for the design of new Al-Er alloys.In this work, Al-Er diffusion couples were successfully prepared by casting-cladding method in Slot Car the atmosphere.

The growth of Al-Er intermetallic compounds at diffusion couple interface during annealing were observed and recorded by High-Temperature Laser-Scanning Confocal Microscopy at 673, 698, 723 and 748 K respectively.The results show that the growth characteristics of Al-Er intermetallic compounds were accord with layer-terraced growth during annealing.The thickness of Baby Tee intermetallic compound was linear with the square root of time at experimental temperature.

The intermetallic compound layer was composed of Al3Er and a very thin AlEr phase.The parabolic growth constants of Al3Er phase at 673, 698, 723 and 748 K were 1.017 × 10−14, 1.

609 × 10−14, 3.111 × 10−14 and 4.76 × 10−14 respectively.

The activation energy of Al3Er phase was (88.4 ± 5.3) kJ/mol and the pre-exponential factor was 7.

126 × 10−8 m2/s.