形狀記憶合金性能增進之研究─總計畫(2/3)

The aim of this 3-year-term integrated project
is focused on the properties improvement of
TiNi-based, Cu-based and Fe-based shape
memory alloys (SMAs). These properties
include shape memory effect (SME),
superelasticity (PE) and damping capacity
(DC). In the second year, TiNi-based and
Fe-based SMAs are investigated. The
experimental results show the severely
cold-rolled and recrystallization annealed
Ti50Ni50 SMA has the 4-steps transformation
sequence due to the different grain-size
distribution. The optimal annealing
conditions can be obtained for the better PE
and DC properties. We also investigate the
reason why TiNi-Fe SMAs can exhibit the
two-way SME after being “constrain-treated”
at R-phase temperature. This feature is
related to the formation of R-phase in
TiNi-Fe SMAs. The addition of Pt in
Fe-30at.% Pd SMA is found to improve its
two-way SME and ferro-magnetic properties.
In the study of Fe-based SMAs, we find that
the SME of Fe59Mn30Si6Cr5 alloy is related to
its texture and can be improved by the
suitable thermo-mechanical treatments. The
experimental results also reveal that the
compressive stress relaxation of
Fe59Mn30Si6Cr5 is not obvious and
approaches to steady-state after 8hrs loading.