N.C.Si
金属学报(英文版)
The effects of heat treatment on the Cu-Zn-Al shape memory alloys with mixed REwere researched with the help of X-ray diffraction and transmission electron micro-scope (TEM).The results show that the shape memory alloys with martensite can beproduced by adding mixed RE and heat treatment processes holding at 820C -880Cfor 15min,quenching into oil,aging at 150C for 15min,and then holding in waterat 50C for 10min.The alloys have the lowest transformation thermal hysteresis.Among the four experimental heat treatment processes the gradationally quenchingmakes the alloy have the highest transformation temperature and quenching into oilor water at room temperature makes the alloy have the largest thermal hysteresis.Mi-crostructure examination shows that aging at 2000C could destroy the substructuresin lathy martensites in the alloy and form a lot of dislocations,and aging at 250℃could cause the bainite transformation in the alloy.
关键词:
Cu-Zn-Al (RE)
,
null
,
null
,
null
N.C.Si
,
Z.H.Jia
,
L.B.Qi
金属学报(英文版)
Effect of carbon, compound RE, quenching temperature, pre-strain and recovery tem-perature on shape memory effect (SME) of Fe-Mn-Si-Ni-C-RE shape memory alloy was studied by bent measurement, thermal cycle training, SEM etc. It was shown that the grains of alloys addition with compound RE became finer and SME increased evidently. SME of the alloy was weakening gradually as carbon content increased under small strain (3). But in the condition of large strain (more than 6), SME of the alloy whose carbon content range from 0.1to 0.12 howed small decreasing range, especially of alloy with the addition of compound RE. Results were also indicated that SME was improved by increasing quenching temperature (>1000℃): The amount of thermal induced martensite increased and the relative shape recovery ratio could be increased to more than 40after 3-4 times thermal training. The relative shape recovery ratio decreased evidently depending on rising of pre-strain. Furthermore, because speed of martensite transition was extremely great under higher tempering temperature (more than 450℃), ε→γ transition completed in 10s meanwhile the relative shave recovery ratio of the allou increased rapidly.
关键词:
Fe-Mn-Si-Ni-C-ER shape memory alloy
,
null
,
null
