论文部分内容阅读
研究目的:为了满足低温系统的材料选择和结构设计对于材料热膨胀特征参数的需求,研发低温条件下精确、快速、方便操作、低成本的热膨胀特征参数测量方法和系统装置。创新要点:完成了卡玛合金箔应变片在77–293 K低温温区敏感系数的修正,保证了基于应变片技术的低温条件材料热膨胀特征参数测量的精度;所研制装置合理的热设计和等速率式温度控制模式使得材料热膨胀特征参数在77–293 K温区的测量可在14小时内快速完成。研究方法:针对77–293 K温区,基于应变片测量方法,研制了采用比例-积分-微分(PID)温控系统的固体材料热膨胀特征参数测量装置(见图2和3)。通过将304不锈钢的测量数据与美国国家标准与技术研究院(NIST)公布数据进行比较,完成了卡玛合金箔应变片在77–293 K低温温区的敏感系数修正(见图7和8)。采用修正后的敏感系数进行无氧铜线性收缩率测量,并与NIST公布数据比较(见图9和表2),验证了该装置在77–293 K低温温区的测量精度。重要结论:获得了77–293 K低温温区卡玛合金箔应变片敏感系数的修正结果;基于修正敏感系数的应变片法测量装置,采用0.3 K/min的等速率式温度控制模式,可实现77–293 K低温温区固体材料热膨胀特征参数的精确、快速测量。
Research purposes: In order to meet the material selection and structural design requirements of low-temperature system for the material’s thermal expansion characteristic parameters, an accurate, rapid, convenient and low-cost thermal expansion characteristic parameter measurement method and system device at low temperature are developed. Innovative points: The completion of the Kama alloy foil strain gauge in the 77-293 K low-temperature temperature coefficient of sensitivity correction, to ensure that the strain gauge technology based on the low temperature thermal expansion material characteristics of the parameters of the measurement accuracy of the device developed by the thermal design and so on The rate-temperature control mode allows the measurement of the material’s thermal expansion characteristics in the 77-293 K temperature range to be completed quickly in 14 hours. Research Methods: Based on the strain gage measurement method, a thermal expansion characteristic parameter measurement device for solid materials using Proportional-Integral-Derivative (PID) temperature control system was developed for the temperature range of 77-293 K (see Figures 2 and 3). By comparing the measured data of 304 stainless steel with those published by the National Institute of Standards and Technology (NIST), the sensitivity correction of the Kama alloy foil strain gauge at a low temperature of 77-293 K was completed (see Figures 7 and 8) . The oxygen free copper linear shrinkage was measured using the corrected sensitivity coefficient and compared with published data from NIST (see Figure 9 and Table 2) to verify the accuracy of the device in the 77-293 K cryogenic temperature range. Important conclusion: The correction results of the sensitivity coefficient of KAM alloy foil in the low temperature range of 77-293 K have been obtained. Based on the strain gage measuring device with the correction sensitivity coefficient, the equal temperature rate control mode of 0.3 K / min can be used 77-293 K Accurate and rapid measurement of thermal expansion characteristic parameters of solid materials at low temperature.