设计研制了1套以4.2 K制冷机为冷源的低温热导率快速测量装置。该装置采用可拆卸的具有独立真空环境的样品测试杆,使得样品测试部件与低温冷源部件分离,从而实现不破坏制冷机冷源真空环境及制冷机不复温的情况下快速更换样品。高真空绝热恒温样品杆通过高导热柔性热桥与制冷机冷头良好热耦合。热导率测试采用稳态绝热纵向热流法。除快速测量的优点外,装置具有很高的测试精度,通过对标准不锈钢304样品的测试比对,证明该装置的测试误差在8%以内、测量温区达到8—300 K。
A novel apparatus based on cryocooler for rapid thermal conductivity measurements was presented.It consists of a dismountable sample test bar on which bulk samples can easily be mounted.The sample test bar was separated from the cold source and has an independent vacuum,so that the sample can be replaced rapidly with cryocooler non-stop.A thermal bridge was used as thermal and mechanical coupling between the sample test bar and the cold head.This fast mounting and measurement system uses a standard steady-state absolute thermal conductivity measurement.The distinction of this system was rapid mounting and measurement of thermal conductivity with high accuracy and precision in data acquisition.The design of this apparatus,measurement specification,and thermal conductivity data on standard stainless steel 304 sample measured in this system were presented.