Popis: |
Welding parameters, i.e. input power and welding time, in the electrofusion welding process are key factors affecting welding quality of polyethylene pipes. The approach of the full-process and real-time video recording for welding process was developed. The cross-section of electrofusion joint was detected by using ultrasonic phased array technology and B-scan imaging technology. Eigen-line at fusion interface was detected, due to the acoustic impedance difference between fusion zone and the solid unfused zone. Further research found that this approach could be used to evaluate the welding parameters by measuring the depth of fusion zone and the moving speed of Eigen-line in recorded videos. Based on the depth decrease of unfused zone, the optimized welding time can be determined. |