| Summary: | 碩士 === 國立交通大學 === 材料科學(工程)研究所 === 81 === In this thesis, the fabrication of Al-Cr-Zr alloy by mechanical
alloying(MA) method and planar flow casting (PFC) method are
reported. Mechanical alloying is a process used for producing
powders having a fine microstructural alloy; In the MA process,
via the repeated cold-working, deformation and fracturing, a
solid-state interdiffusion reaction occurring, and the powders
with ultrafine microsturcture was formed finally. The milling
intensity strongly affects the phase formation, resulting in
amorphous or crystalline material for milling at low and high
milling intensity, respectively. Furthermore, the various
phases can be In this experiment, the planar flow casting was
employed to produce Al-3Cr-3Zr, Al-3Cr and Al-3Zr rapidly
solidified ribbons. The phase transformation processes of the
ribbons and and MA powders at a continuous heating rate were
studies by differential scanning calorimetry. The precipitaion
temp. of Al3Cr2 and Al3Zr in the supersaturated solid solution
are ca. 500℃ and 400℃, respectively. The DSC studied aoso
shed light on recovery, recrystallization and grain growth
temp. of MA powder. All these efforts done are helpful for
parameter choices in further thermal-mechanical treatments of
MA powders and PFC ribbons.
|
|---|
