Dr. Zhili FENG,

Distinguished R&D Staff, Oak Ridge National Laboratory，USA

Topic

    Intelligent Welding Quality Control with Reversed Electrode Images

Abstract

    Weld imperfections or defects such as incomplete penetration and lack of fusion are critical issues that affect the integrated of welding component. The molten weld pool geometry is the major source of information related to the formation of these defects. In our recent research, a new visual sensing system has been designed and set up to obtain weld pool images during welding. The interference of arc light in the image was significantly reduced through the narrow band pass filter and laser based auxiliary light source. New computer vision algorithms based on reversed electrode image（REI） were developed to measure 3D weld pool surface geometry. Supervised machine learning was used to develop the capability to predict, in real-time, the welding defect including incomplete penetration and lack of fusion with the key features extracted from weld pool images. Finally, an integrated self-adaptive close loop control system consisting the non-contact visual sensor, machine learning based defect predictor, and welding power source was developed for real-time welding penetration control. These methods were validated on butt-joint and U-groove welding which are commonly used in manufacturing.

Biography

    Dr. Zhili Feng is Group Leader of Materials Processing and Joining Group, and a Distinguished R&D Staff of Oak Ridge National Laboratory. He manages a diverse R&D portfolio aimed at addressing the materials processing and joining needs from automotive, aerospace, nuclear, petrochemical and power generation industries. His primary interest is in thermal-mechanical-metallurgical behaviors of materials during processing and joining. Most recent work included integrated computational welding engineering (ICWE), proactive weld residual stress control and management, friction stir welding and processing, characterization of weld by advanced neutron and synchrotron scattering, and novel solid-state joining processes of dissimilar metals. Dr. Feng received his PhD in Welding Engineering from the Ohio State University. He is a Fellow of the American Welding Society, a Joint Faculty Professor of University of Tennessee, Knoxville, and Guest Professor of Tsinghua University. Dr. Feng has broad interactions with industry, and extensive experience in solving critical industry problems.