为开发力敏性能更为优异的复合材料薄膜,首先,通过液相还原法制备了粒径约为100nm的纳米Fe50Ni50粉体,并通过液态混合分散工艺将纳米粉体与丁基橡胶(IIR)混合分散;然后,通过机械混炼及压制得到了粉体分布均匀、含量为65wt%的纳米Fe50Ni50粉体/IIR复合材料薄膜;最后,研究了在连续加载/卸载速度为0.10mm/min、测试频率为1kHz的条件下,纳米Fe50Ni50粉体/IIR复合材料薄膜的力敏特性。结果表明:液态混合分散工艺可使Fe50Ni50粉体在复合材料薄膜中达到纳米级均匀分散效果;当压应力为0.20~0.90 MPa时,薄膜越厚,其标准偏差越大,力敏稳定性越差;随压应力增大,厚度为185μm的薄膜在加载阶段的阻抗近似线性下降,力敏灵敏度稳定在40~60范围内,标准偏差约为1~2。所得结论表明在压应力为0.20~0.90MPa时,制备的薄膜具有优异的力敏特性。
In order to develop the composite film with better force sensitive characteristic,nano Fe50Ni50 powders whose particle size was about 100 nm were prepared by liquid phase reduction method firstly,and the nano powders were mixed and dispersed with butyl rubber(IIR)by liquid phase mixing dispersing method.Then,the nano Fe50Ni50 powders/IIR composite films whose powders were well dispersed and content was 65wt% were obtained by mechanical mixing and pressing.Finally,the force-sensing characteristics of nano Fe50Ni50powders/IIR composite films were investigated under the conditions of continuous uploading/downloading speed was 0.10 mm/min and test frequency was 1kHz.The results show that liquid phase mixing dispersing method can make the Fe50Ni50 powders achieve uniform dispersion effect at nano-scale in the composite films.When compressive stress is 0.20-0.90 MPa,the thicker the film is,the larger its standard deviation is,and the worse the force sensitivity stability is.With compressive stress increasing,impedance of the film which thickness is 185μm decreases linearly approximately during uploading period,and force sensitive degree is stable in range of 40-60,the standard deviation is about1-2.The conclusions obtained show that the prepared film has excellent force sensitive characteristic when the compressive stress is 0.20-0.90 MPa.