针对聚合物熔体在微尺度通道中流动时的黏性耗散效应对其流动行为的影响，通过自行构建的带有温度传感器和超声振子的微注塑成型试验系统，采用单因素成型试验方法，对聚丙烯(Polypropylene, PP)和高密度聚乙烯(High-density polyethylene, HDPE)两种聚合物材料在不同工艺参数和超声外场作用下，流经矩形截面微通道时由黏性耗散效应引起的通道出口熔体温升进行试验测量。结果表明，微通道中熔体的黏性耗散效应随注射速度的增加而增强，随入口熔体温度和模具温度的升高而减弱；与不加超声振动相比，施加超声振动使两种材料的微通道出口熔体温升值明显升高；但材料自身的微观分子结构及其热物理性能不同，其温升增幅差别较大。试验注射速度下，施加超声振动比不加超声振动时的PP熔体温升增幅高出34.7%，而HDPE熔体的温升增幅则高达71.7%。当超声频率和工艺参数一定时，增大超声功率使PP熔体的微通道出口温升增加了24.8%，HDPE熔体的温升增加了83.6%。可见施加超声外场作用能使微通道中聚合物熔体的黏性耗散效应明显增强。

For viscous dissipation effect of the polymer melts flowing in micro-scale channel on their flow performance. The micro-injection molding experimental system with temperature sensors and ultrasonic field are designed. The temperature rises at the outlet of the rectangular cross-section micro-channel caused by viscous dissipation at different process parameters and ultrasonic power changes are investigated, using polypropylene(PP) and high-density polyethylene(HDPE) two polymer melts by the single factor molding experiments. The results show that the viscous dissipation effect of the polymer melts flowing in micro-scale channels is enhanced with the increase of injection rate, while it can be weakened by the rise of inlet melts temperature and mold temperature and the outlet temperature rise of the two materials with ultrasonic vibration can be significantly higher than that without ultrasonic vibration. However, their temperature increases vary greatly for microscopic molecular structures of different materials and their thermo-physical properties. PP melt temperature increase applying ultrasonic vibration is 34.7% higher than that without ultrasonic vibration at the set injection speed, while it is 71.7% for HDPE. But the under a certain ultrasonic frequency and process parameter，increasing the ultrasonic power make PP melt temperature increase by 24.8%, while it is 83.6% for HDPE. It’s obvious that the viscous dissipation effects of polymer melts flowing the micro channel can be enhanced by applying ultrasonic field.