Controlled Heat and Metal Transfer in Gas Metal Arc Welding-Base for New Rapid Prototyping Technique

随着对3-D焊接研究的继续，直接从3-D CAD数据生产完全致密、结构坚固的金属部件的能力越来越接近现实。本课题将为最新的快速成型技术之一——三维焊接零件尺寸精度控制技术的发展奠定基础。在3-D焊接中，熔化的焊丝的液滴被分离出来形成金属沉积物。通过控制液滴的沉积，可以实现快速成型或快速制造。金属零件可以一层一层地制造，液滴大小和剥离时间决定了零件的最终形状，以及它的机械和冶金性能。提出的基于三维焊接的快速成型系统，通过结合传热传质控制，解决了零件尺寸公差和机械及冶金性能同时几何调节的挑战。与其他快速成型技术相比，3d焊接具有许多潜在的优势。通过引入焊枪的机器人控制，最终的零件可能在尺寸和几何形状上有很大的变化。3d焊接将允许直接生产由不同材料制成的零件。在目前的快速成型技术中，三维焊接具有运行成本低、加工时间短、性能可控等特点。理论和实验方法的结合将为更好地理解物理和优化这一创新技术提供基础。

9732848 Kovacevic As research into 3-D welding continues, the ability to produce fully dense, structurally strong metal parts directly from 3-D CAD data comes nearer to reality. This project will lay the foundation for developing a technique of controlling the dimensional accuracy of parts obtained by 3-D welding, one of the newest rapid prototyping methods. In 3-D welding, a droplet of the melted electrode wire is detached to form a metallic deposit. Rapid prototyping or rapid manufacturing may be accomplished by controlled deposition of the drops. A metallic part can be made layer by layer, with the drop size and detachment timing defining the resultant shape of the part, as well as its mechanical and metallurgical properties. The proposed system for rapid prototyping based on 3-D welding addresses the challenge of simultaneous geometric regulation of dimensional tolerances and mechanical and metallurgical properties of the part, by combined heat and mass transfer control. 3-D welding has the potential of offering numerous advantages over other rapid prototyping techniques. Final parts may be constructed with a large variation in dimensions and geometry by the introduction of robotic control of the welding torch. 3-D welding would allow the direct production of parts made of different materials. It is projected that the very low operating cost, the rapid processing time, and the control of properties makes 3-D welding unique among current rapid prototyping techniques. The combination of the theoretical and experimental approach will provide better understanding of the physics and the basis to optimize this innovative technique.