Plume Heat Transfer in Laser Processing of Materials

材料激光加工中的羽流传热

• 批准号: 9113151
• 负责人: M Q Brewster
• 金额: $ 20.07万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-08-15 至 1996-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9113151&HistoricalAwards=false
• 关键词: Plume; Heat; Transfer; Laser; Processing

This study is an investigation of the mechanisms of heat transfer associated with plume formation occurring during the interaction of laser radiation with metal targets. The primary objective of the study is the development of techniques which can be used to determine the relative importance of plume absorption, scattering, and emission on coupling of laser energy into metal targets. The methods used include high speed photography, target temperature measurement, plume light scattering and transmission measurements, and calibrated plume emission spectroscopy. A pulsed Nd-YAG laser is used as the primary source of incident laser radiation at flux levels of 105 W/cm2 and greater. Aluminum and aluminum alloy materials are used as targets. Another objective of this study is the investigation of the role of the assist gas on plume ionization and coupling of laser energy into the workpiece. The influence of molecular oxygen on degree of plume ionization is studied by performing tests in various atmospheres with and without molecular oxygen. The significance of this study is that a clearer understanding of the heat transfer mechanisms associated with plume formation is expected to be obtained. This study will help accomplish the long term goal of this research program which is to provide an understanding of heat transfer mechanisms in laser target interaction so that lasers may be utilized to their full advantage in materials processing.

这项研究是对激光辐射与金属靶标相互作用期间发生的与羽状形成相关的传热机理的研究。 该研究的主要目的是开发技术，可用于确定羽流，散射和发射对激光能量偶联到金属靶标的相对重要性。 所使用的方法包括高速摄影，目标温度测量，羽流散射和传输测量以及校准的羽状发射光谱。 脉冲ND-YAG激光用作105 W/cm2及更大的通量水平的入射激光辐射的主要来源。 铝和铝合金材料用作靶标。 这项研究的另一个目的是研究辅助气体在羽流和激光能量偶联中的作用。 通过在有或没有分子氧的各种大气中进行测试，研究了分子氧对羽流电离程度的影响。 这项研究的意义在于，预计将获得对与羽流形成相关的传热机制的更清晰的了解。 这项研究将有助于实现该研究计划的长期目标，该计划将对激光靶点相互作用中的传热机制提供理解，以便可以将激光器在材料处理中充分利用。