In the present study, online monitoring of melt-based laser forming using a 2 kW Yb-fibre laser to understand the effect of partial sheet melting on bending behavior and mechanism to achieve precise deformation is investigated. A 1 mm thick 304L stainless steel sheet was used as substrate. The melt and non-melt-based sheet deformation and temperature signals were monitored using a laser-based non-contact type displacement sensor and an IR pyrometer, respectively for five consecutive scans on the same path having laser power, scan speed and spot diameter as input parameters. Variation in melt depth with process parameters and its effect on counter bending angle, net bending angle and significance of melt percentage with respect to sheet thickness on dictating the bending behavior was investigated. The bending mechanism reported in case of melt-based laser forming was found to vary from established solid metal sheet forming mechanisms and was termed as “melt-based TGM” mechanism. A maximum bending angle of 9.2° was obtained after five scans with 82 μm of melt depth. Microstructural and Phase variations of the melt and non-melt zone were studied for understanding their effects on material properties for melt–based laser forming. Finally, the mechanical behavior like modulus, Nano hardness and micro hardness of the melt and non- melt formed samples were studied to understand the applicability of melt-based laser formed sheets.

在本研究中，对使用2 kW Yb光纤激光器的基于熔体的激光成形进行在线监控，以了解部分板熔对弯曲行为和实现精确变形的机理的影响。将1mm厚的304L不锈钢板用作基材。使用基于激光的非接触式位移传感器和红外高温计分别监测基于熔体和非熔体的片材变形和温度信号，分别在同一路径上连续进行五次扫描，扫描的激光功率，扫描速度和光斑直径为输入参数。研究了熔体深度随工艺参数的变化及其对反向弯曲角，净弯曲角的影响以及熔体百分率相对于板材厚度对决定弯曲行为的影响。发现在基于熔融物的激光成形的情况下报道的弯曲机制与已建立的固体金属板形成机制不同，被称为“基于熔融物的TGM”机制。在熔融深度为82μm的情况下进行五次扫描后，最大弯曲角度为9.2°。研究了熔融区和非熔融区的微观结构和相变，以了解它们对基于熔融的激光成型的材料性能的影响。最后，研究了熔体和非熔体成型样品的模量，纳米硬度和显微硬度等机械性能，以了解熔体基激光成型片材的适用性。研究了熔融区和非熔融区的微观结构和相变，以了解它们对基于熔融的激光成型的材料性能的影响。最后，研究了熔体和非熔体成型样品的模量，纳米硬度和显微硬度等机械性能，以了解熔体基激光成型片材的适用性。研究了熔融区和非熔融区的微观结构和相变，以了解它们对基于熔融的激光成型的材料性能的影响。最后，研究了熔体和非熔体成型样品的模量，纳米硬度和显微硬度等机械性能，以了解熔体基激光成型片材的适用性。