【作者】 梁伟；

【导师】 王铀；

【作者基本信息】 哈尔滨工业大学 ， 材料物理与化学， 2010， 硕士

【摘要】 电阻应变式测力称重传感器在高精度机械测量领域中有着广泛的应用,但目前国内的传感器设计、制造、检验技术,尤其是应变片基底材料的制造工艺非常落后。为制备高精度、高稳定性的应变片,本课题研制了一种称重传感器应变片基底胶并对其性能进行了研究。主要研究内容和结果如下:首先,研究了作为基底材料基体的环氧树脂胶粘剂的配方,利用差示扫描量热仪(DSC)初步确定了胶粘剂的固化温度,并对胶粘剂进行了性能测试。90°剥离实验结果显示,胶粘剂与康铜箔材具有很高的胶结强度,并具有良好的耐湿热老化性能。其次,采用原位及离位傅立叶变换红外光谱(FTIR)技术研究了环氧树脂胶粘剂的固化动力学,得出该体系的固化动力学参数,进而得到了固化时间、固化温度与环氧基转化率之间的方程式,确定了具体的固化工艺。同时在研究中发现,表征固化动力学时,原位法在时间轴上是准确的,但温度轴上存在一定偏差;而离位法在温度轴上是准确的,但时间轴上存在一定偏差。两种方法可互补校正。再次,利用动态力学分析(DMA)测试了该基底胶的玻璃化转变温度,以及利用热失重(TG)对基底胶的耐热性进行了分析,结果表明基底胶具有较好的热稳定性。在之后的FTIR对固化后树脂分子结构中官能团的热稳定性的比较中发现,树脂结构中所氮原子相连的亚甲基往往是最薄弱的地方,最先发生分解。最后,利用DMA蠕变模式考察了基底胶的蠕变性能,并讨论了温度、应力对基底胶蠕变性能的影响。应变及应变回复测试结果表明基底胶在常温条件下具有良好的回复性,可满足传感器应变片的使用要求。更多还原

【Abstract】 Strain gauge load cell is widely used in mechanical high precision measurements. At present, load cell design, manufacture and test in china, especially the strain gage backing material are laggard a lot. To manufacture high precision, long-term stability strain gauge, a novel base adhesive was developed and its cure kinetics and performance were studied in this paper. The main results are summarized as follows:First, formulation tailoring and curing process of epoxy resin adhesive have been studied, and the peel strengths were tested. The curing temperatures are obtained following the result of curing reaction heat flow tested by DSC. The results showed that the modified epoxy resin was satisfied, and could stick well to constantan alloy. The tests of resistance to hydrothermal ageing showed that the adhesive has excellent resistance to weathering.Second, the cure kinetics of epoxy resin adhesive was studied by both in-situ and ex-situ Fourier transform infrared (FTIR) spectroscopy. From fitting to experimental data the kinetics parameters were estimated and the equation among cure time, cure temperature, and conversion of epoxide were obtained, which will be greatly useful in deciding the epoxy resins cure process. The research also found that ex-situ FTIR is more accurate than in-situ FTIR as regard to the time term in describing the kinetics. The two methods are mutually complementary.Third, the glass transition temperature of base adhesive was determined by dynamic mechanical analysis (DMA) and thermal properties were determined by thermal gravimetry (TG). And the relative thermal stability of function groups was investigated by FTIR. The result showed that methyl and methylene group are the relative unstable function groups and are liable destroyed under high temperature.Forth, the glass transition temperature, creep and strain recovery of base adhesive were determined by dynamic mechanical analysis (DMA). The influences of temperature and stress imposing on creep were also discussed respectively. Strain and strain recovery tests showed that the base adhesive has a good recovery percentage and fulfill the requirements of strain gauge load cell.更多还原