Dynamic thermo-mechanical properties of evaporated TiNi shape memory thin film
Dynamic thermo-mechanical properties of evaporated TiNi shape memory thin film
复制标题
蒸发TiNi形状记忆薄膜的动态热机械性能
DOI：
10.1016/s0924-4247(99)00222-8
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发表时间：
1999
影响因子：
4.6
通讯作者：
Kazuhiro Kato
中科院分区：
文献类型：
--
作者：
E. Makino;T. Shibata;Kazuhiro Kato
使用凸出法研究了形状记忆合金（SMA）薄膜对热循环的形状恢复和再偏转响应。它通过闪蒸沉积，标称成分为 50 at.% Ti-50 at.% Ni，厚度约为 6 μm。从硅基板上剥离并进行真空退火以记忆初始扁平形状后，通过400 kPa的加压使其变形为直径5毫米的帽状。然后，通过施加 100 ms 电压脉冲，通过不同能量的电阻加热恢复其初始形状。在这些形状恢复和再偏转循环期间，使用激光位移计连续测量位移随时间的变化。由于逆马氏体转变，薄膜在超过 1 J 的加热能量下表现出形状恢复。形状恢复引起的位移随着加热能量的增加而增加，在超过2J的能量下在100μm左右达到饱和。加热完成后，由于压力下的马氏体转变，薄膜再次发生偏转。在能量为 2.1 J 时，每个形状恢复和再偏转循环的周期约为 600 ms。在高达 1000 次循环（这是测试的最大热循环次数）时，它表现出稳定的形状恢复和再偏转性能。最后，还粗略估计了此类 SMA 微型泵可能预期的泵送压力和流量。
The shape recovery and re-deflection responses of shape memory alloy (SMA) thin film to thermal cycles were investigated using the bulge method. It was deposited by flash evaporation and had a nominal composition of 50 at.% Ti–50 at.% Ni and a thickness of about 6 μm. After being released from silicon substrates and undergoing vacuum-annealing to obtain memorisation of an initial flat shape, it was deformed into a cap shape of 5 mm in diameter by pressurisation at 400 kPa. Then, by applying 100 ms voltage pulses, its initial shape was recovered by resistive heating at various energies. During these shape recovery and re-deflection cycles, change in displacement with time was measured continuously using a laser displacement meter. The thin film exhibited shape recovery at energies for heating of more than 1 J due to reverse martensitic transformation. Displacement due to shape recovery increased with increasing energy for heating, reaching saturation at around 100 μm at energies of more than 2 J. After heating was completed, the thin film deflected again due to martensitic transformation under pressure. The period for each shape recovery and re-deflection cycle was about 600 ms at an energy of 2.1 J. It exhibited stable shape recovery and re-deflection properties at up to 1000 cycles, which was the maximum number of thermal cycles tested. Finally, the pumping pressures and flow rates which might be expected with such an SMA micropump were also roughly estimated.