超薄微束等离子弧焊熔池的高频诱发振荡耦合机理和成形稳定效应

For the tough defect problems of easy to be over penetrated and easy to deform in welding ultra-thin fine precision structure via fine micro-plasma arc welding, the projective of this research is to get high-quality welding without defections of over penetration and deformation under premise of arc stability in the ultra-low current micro-plasma arc welding for such ultra-thin fine precision structure. A coupling between the natural oscillation, induced by the arc heat and the molten pool force, and molten pool high-frequency induced oscillation caused by molten pool high-frequency AC wave plasma arc force, is put forward under the high-frequency pulse mode. Based on research of the characteristics that the natural oscillation is added by the high-frequency induced oscillation in molten pool under the situation of full penetration, various physical quantities intrinsic relationships during coupling of molten pool natural oscillation and high frequency induced oscillation under high-frequency pulsed mode will be researched further. Meanwhile, coupling model of high frequency arc and high-frequency oscillation molten pool will be approached. Based on the model, the mechanism of sensitivity reduction to produce defects of over penetration and deformation, affect of molten pool dynamic process on welding geometry, will be predicted further. This high-quality and ultra-precision processing will provide a strong theoretical foundation for the high-tech fields of modern industry and defense technology, precision preparation of new materials and materials modification applications.

针对超薄细精密结构件精细微束等离子弧焊接成形易烧穿易变形的棘手缺陷问题，以保证超薄细精密结构件在超小电流微束等离子弧焊电弧稳定前提下无变形及烧穿缺陷的高质量焊接成形为目标，提出了高频脉冲模式下电弧热和熔池合力的熔池固有振荡与高频交流波等离子体电弧力的熔池高频诱发振荡之间的耦合，在研究焊透熔池的固有振荡叠加熔池高频诱发振荡特征的基础上，研究高频脉冲下熔池固有振荡和高频诱发振荡耦合的各物理量之间内在联系，建立完成高频电弧和高频熔池耦合的模型，基于模型研究烧穿及变形缺陷产生敏感度降低的机理和焊接熔池形状动态过程影响的焊接成形预测。这将高质量地实现材料的超精度加工，为现代工业和国防科技的高技术领域新材料精密制备和材料改性应用提供有力的理论基础。

本研究针对超薄细精密结构件精细微束等离子弧焊接成形易烧穿易变形的棘手缺陷问题，以保证超薄细精密结构件在超小电流微束等离子弧焊电弧稳定前提下无变形及烧穿缺陷的高质量焊接成形为目标，通过提出以高频脉冲模式下电弧热和熔池合力的熔池固有振荡以及高频微束等离子弧焊熔池合力的高频诱发振荡，来探讨超薄细精密结构件精细微束等离子弧焊接降低烧穿及变形缺陷产生敏感度的研究思路，协同研究超薄板（100 μm及以下板厚）高频微束等离子弧焊电弧动态能量密度分布、熔池动态过程、及焊接成形、焊接缺陷的交叉学科关键技术问题。.重点研究了高频脉冲微束等离子弧焊电弧多动态物理场耦合模型及其分布动态变化的内在关系、具有热惯性特征的实际高频电弧热输入下的超薄结构件精细焊接熔池动态熔化和熔池合力作用下的熔池液态金属的动态流动过程的耦合及其对超薄结构件焊接成形尺寸的影响和变形及烧穿缺陷产生的影响、电弧热和熔池合力共同作用下的熔池热力学动态平衡过程中的熔池固有振荡和熔池高频诱发振荡的超薄板焊接熔池流动和形态模型及其对焊接成形的影响机制和对超薄细结构件精细焊接烧穿及变形敏感度的降低作用、超薄板脉冲微束等离子弧焊熔池高频诱发振荡焊接成形的微观组织优化、超薄板脉冲微束等离子弧焊接多物理量耦合的成形控制和缺陷抑制。.项目研究成果同时从基础性理论研究和工艺实验结果揭示了超薄板（100 μm及以下板厚）高频微束等离子弧焊接在焊接熔池高频脉冲诱发振荡下的烧穿变形缺陷产生敏感度的降低机理和焊接成形控制的脉冲参数影响机制，在与其密切相关的各关键基础性问题的研究取得了突破性进展，解决了超薄细精密结构件精细微束等离子弧焊的焊接成形质量问题，成功实现了100 μm超薄不朽钢板、100 μm超薄镍基合金、50 μm超薄钛箔、280 μm超细丝网的无缺陷精密焊接，为现代工业和国防科技的高技术新材料精密制备和材料改性应用奠定了全面的理论和工艺研究基础。