Metal additive manufacturing has been widely used in many fields. It is important to realize the support-free deposition of metal parts since the supporting structure is hard to remove. Some of the existing support-free methods are complicated by generating curved layers, which may also cause defects between layers. This paper presents a support-free wire and arc additive manufacturing (WAAM) method based on surface/interior separation and surface segmentation. A metal part model is first divided into the surface and interior solid (IS), and the surface is segmented further into the overhanging area (OA) and the nonoverhanging area (NOA). The OA is deposited with multiaxis motion of a robot to avoid the overhanging phenomenon. The NOA and IS are deposited vertically in the traditional way. Path planning is performed by alternatively depositing the OA and the NOA and IS. To reduce the number of voids between layers, an IS filling method is proposed in which the adjacent layers are filled with interlaced passes. The density of the part with interlaced passes increases by 1.9 % compared with the part with noninterlaced passes. Two typical models are deposited without any support to verify the feasibility of the proposed methods.

金属增材制造已广泛应用于许多领域。由于支撑结构难以去除，因此实现金属部件的无支撑沉积非常重要。现有的一些无支撑方法由于生成弯曲层而变得复杂，这也可能导致层间缺陷。本文提出了一种基于表面/内部分离和表面分割的无支撑线材和电弧增材制造 (WAAM) 方法。金属零件模型首先分为表面和内部实体 (IS)，然后将表面进一步分割为悬垂区域 (OA) 和非悬垂区域 (NOA)。OA是通过机器人的多轴运动沉积的，以避免出现悬垂现象。NOA 和 IS 以传统方式垂直沉积。路径规划是通过交替放置 OA 和 NOA 和 IS 来执行的。为了减少层间空隙的数量，提出了一种IS填充方法，其中相邻层用交错通道填充。与具有非交错通道的部件相比，具有交错通道的部件的密度增加了 1.9%。在没有任何支持的情况下存放了两个典型模型以验证所提出方法的可行性。