Scholarlink

<p>Microstructure and geometry are two important characteristics of a processed part that researchers aim to control during laser material processing (LMP). The current study introduces a novel method to monitor these characteristics through the innovative use of an infrared pyrometer. The setups involve oscillating the pyrometer focus about the molten pool region. The focal spot of the pyrometer for temperature measurement is oscillated across and along the laser scanning direction to obtain the width of the molten pool and its thermal history, respectively, in real-time. Two different methods for oscillating the pyrometer focal spot have been implemented. In one, the pyrometer head was oscillated along the molten pool using an oscillating table between two points outside the molten pool through the pool. The thermal cycles, peak temperatures, heating rates and cooling rates during the laser processing could be obtained in real time with minimal computation at a data acquisition rate of 300 ms. In another method, an oscillating mirror was used to oscillate the focal spot of a stationary pyrometer across the molten pool width. The magnitudes of the molten pool width are obtained in real-time at a data acquisition rate of 50 ms during every half-oscillation by identifying the transition point from liquid to solidus temperature at the boundary of the molten pool. The system’s effectiveness in obtaining the thermal history and track width was demonstrated using laser re-melting and laser deposition experiments. Incorporated with a feedback control system, this technique could be used to adaptively control the geometric features and microstructure in different LMP modalities.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

A novel technique for real-time monitoring of molten pool geometry and thermal history in laser material processing using an oscillating pyrometer

  • 期刊论文

  • 发表日期：

    2026年3月30日

查看全文
  • Amal Madhavan Nair,
  • Amlan Mahata,
  • Ashish Kumar Nath,
  • Asimava Roy Choudhury

摘要

Microstructure and geometry are two important characteristics of a processed part that researchers aim to control during laser material processing (LMP). The current study introduces a novel method to monitor these characteristics through the innovative use of an infrared pyrometer. The setups involve oscillating the pyrometer focus about the molten pool region. The focal spot of the pyrometer for temperature measurement is oscillated across and along the laser scanning direction to obtain the width of the molten pool and its thermal history, respectively, in real-time. Two different methods for oscillating the pyrometer focal spot have been implemented. In one, the pyrometer head was oscillated along the molten pool using an oscillating table between two points outside the molten pool through the pool. The thermal cycles, peak temperatures, heating rates and cooling rates during the laser processing could be obtained in real time with minimal computation at a data acquisition rate of 300 ms. In another method, an oscillating mirror was used to oscillate the focal spot of a stationary pyrometer across the molten pool width. The magnitudes of the molten pool width are obtained in real-time at a data acquisition rate of 50 ms during every half-oscillation by identifying the transition point from liquid to solidus temperature at the boundary of the molten pool. The system’s effectiveness in obtaining the thermal history and track width was demonstrated using laser re-melting and laser deposition experiments. Incorporated with a feedback control system, this technique could be used to adaptively control the geometric features and microstructure in different LMP modalities.