The laser directed energy deposition (laser-DED) Additive Manufacturing (AM) has unique capability of being able to deposit functional geometries on existing components. Many times the required geometries contain sharp features such as abrupt turns. During deposition such features introduces heterogeneity in the build-part and adversely the structural integrity of the part. The slower deposition speeds due to the deceleration and acceleration of the motion controller around sharp features in a geometry leads to defects such as variable wall thickness, porosity, lack of fusion, and cracks. In many cases, the functional geometries are single-walled and there is not enough material volume to machine the deposited material. Such cases pose a unique challenge to the laser-DED techniques capabilities. In this work, single walled cubical Ti6Al4V structure with sharp and rounded corners were fabricated using laser Directed Energy Deposition (DED). Cross sectional and build plane coupons were extracted from each sample for microstructure and defect analysis. Results show that inclusion of small rounded corners (radii of 0.5 and1.0 mm) leads to consistent deposition speeds. Defect density measurements, using optical microscope, showed reduction of defects from 6.8 ± 0.35 % to a virtually defect-free structure for samples with the rounded corners. The results also indicated that consistent deposition speed around rounded corners improved homogeneity in the resulting microstructure as compared to the geometry with sharp corners when processed under identical parameters.

激光定向能量沉积（laser-DED）增材制造（AM）具有能够在现有组件上沉积功能几何形状的独特功能。很多时候，所需的几何形状包含尖锐的特征，例如突然的转弯。在沉积过程中，这些特征会在构建部件中引入异质性，并不利地影响部件的结构完整性。由于运动控制器围绕几何形状中的尖锐特征进行减速和加速而导致的较慢沉积速度会导致缺陷，例如壁厚可变，孔隙率大，缺乏熔合和裂纹。在许多情况下，功能几何结构是单壁的，没有足够的材料量来加工沉积的材料。这种情况对Laser-DED技术的能力提出了独特的挑战。在这项工作中 使用激光定向能量沉积（DED）制造了具有尖锐和圆角的单壁立方Ti6Al4V结构。从每个样品中提取横截面和构建平面试样，以进行微观结构和缺陷分析。结果表明，包含小的圆角（半径为0.5和1.0 mm）会导致一致的沉积速度。使用光学显微镜进行的缺陷密度测量表明，对于带有圆角的样品，缺陷从6.8±0.35％减少到了几乎没有缺陷的结构。结果还表明，与在相同参数下加工时具有尖角的几何形状相比，在圆角附近的一致沉积速度提高了所得微结构的均匀性。从每个样品中提取横截面和构建平面试样，以进行微观结构和缺陷分析。结果表明，包含小的圆角（半径为0.5和1.0 mm）会导致一致的沉积速度。使用光学显微镜进行的缺陷密度测量表明，对于带有圆角的样品，缺陷从6.8±0.35％减少到了几乎没有缺陷的结构。结果还表明，与在相同参数下加工时具有尖角的几何形状相比，在圆角附近的一致沉积速度提高了所得微结构的均匀性。从每个样品中提取横截面和构建平面试样，以进行微观结构和缺陷分析。结果表明，包含小的圆角（半径为0.5和1.0 mm）会导致一致的沉积速度。使用光学显微镜进行的缺陷密度测量表明，对于带有圆角的样品，缺陷从6.8±0.35％减少到了几乎没有缺陷的结构。结果还表明，与在相同参数下加工时具有尖角的几何形状相比，在圆角附近的一致沉积速度提高了所得微结构的均匀性。使用光学显微镜进行的缺陷密度测量表明，对于带有圆角的样品，缺陷从6.8±0.35％减少到了几乎没有缺陷的结构。结果还表明，与在相同参数下加工时具有尖角的几何形状相比，在圆角附近的一致沉积速度提高了所得微结构的均匀性。使用光学显微镜进行的缺陷密度测量表明，对于带有圆角的样品，缺陷从6.8±0.35％减少到了几乎没有缺陷的结构。结果还表明，与在相同参数下加工时具有尖角的几何形状相比，在圆角附近的一致沉积速度提高了所得微结构的均匀性。