Magnetorheological pressure forming (MRPF) has shown great flexibility in process control by adjusting the mechanical property of MR fluid. However, the regulation of flexible-die property at present is holistic. In this paper, MRPF based on subregional flexible-die control was proposed, which makes the MR fluid show different force transfer characteristics to meet the requirements of flexible-die performance in different areas. Two kinds of non-uniform magnetic fields were established using the combination of coil and iron core groups based on the measurement and finite element simulations. The MRPF experiments of the Al1060-O sheet using the holistic and subregional flexible-die control methods were conducted. The effects of subregional flexible-die control on loading curve, strain distribution, configuration, wall thickness thinning rate, and fracture characteristics were analyzed. Compared with the case that the specimen ellipticity changes little under the central-dominated magnetic field (CMF), the ellipticity gradually decreases under the fringing-dominated magnetic field (FMF) with the increase of the current. The fracture modes can be divided into three types, and the fracture position transfers from the center of the specimen to the circle of R10mm and then to the die fillet area. The influence mechanism of subregional flexible-die control on sheet deformation behavior and fracture mode is further clarified. The non-uniform distribution of cavity pressure and friction conditions caused by the magnetorheological effect is the main factor affecting the stress states and final deformation behavior of sheet metal. This study provides a new path for intelligent control in sheet metal forming of complex thin-walled parts.

磁流变压力成形 (MRPF) 通过调整 MR 流体的机械性能在过程控制中表现出极大的灵活性。但是，目前对柔性模具性能的调控是整体性的。本文提出了基于分区柔性模具控制的MRPF，使MR流体呈现不同的力传递特性，以满足不同区域对柔性模具性能的要求。在测量和有限元模拟的基础上，利用线圈组和铁芯组的组合建立了两种非均匀磁场。进行了使用整体和分区柔性模具控制方法的 Al1060-O 板的 MRPF 实验。次区域柔性模具控制对加载曲线、应变分布、构型、壁厚减薄率的影响，并对断裂特征进行了分析。与在中心主导磁场（CMF）下样品椭圆率变化不大的情况相比，在边缘主导磁场（FMF）下，椭圆率随着电流的增加而逐渐减小。断裂方式可分为三种，断裂位置从试件中心向R10mm的圆转移，再到模具圆角区。进一步阐明了分区柔性模具控制对板材变形行为和断裂模式的影响机理。由磁流变效应引起的型腔压力和摩擦条件的不均匀分布是影响钣金应力状态和最终变形行为的主要因素。