Laser directed energy deposition (LDED) is one of the metal additive manufacturing processes for fabricating complex shaped metallic components directly from a digital model using high power lasers and metallic powder. To fabricate components with minimum inaccuracies in build geometry and maximum build economy, optimization of process parameters is significant. In the present work, an experimental investigation is carried out to optimize LDED parameters (laser power, scanning speed, powder feed rate, rastering pattern, and build orientation) using an L9 orthogonal array as per the Taguchi design, by building an effective portion of cube geometry. The influence of input process parameters on build geometry and build economy is investigated, and grey relational (GR) analysis is carried out for multiobjective analysis. ANOVA shows that the most significant parameter influencing inaccuracy along the length, inaccuracy along the height, surface unevenness, and edge deviation error is build-orientation, while inaccuracy along the width, build time, and build fraction are largely influenced by laser energy per unit length. GR analysis shows that the build orientation is the most significant parameter. This study is important for considering build geometry and build economy during LDED.

中文翻译：

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在基于激光定向能量沉积的增材制造过程中研究构建几何特征

激光定向能量沉积 (LDED) 是一种金属增材制造工艺，用于使用高功率激光器和金属粉末直接从数字模型制造复杂形状的金属部件。为了制造具有最小构建几何误差和最大构建经济性的组件，工艺参数的优化非常重要。在目前的工作中，根据田口设计使用 L9 正交阵列进行实验研究，以优化 LDED 参数（激光功率、扫描速度、送粉速度、光栅图案和构建方向），通过构建有效部分立方体几何。研究了输入工艺参数对构建几何形状和构建经济性的影响，并针对多目标分析进行了灰色关联 (GR) 分析。方差分析表明，影响长度方向不准确度、高度方向不准确度、表面不平整度和边缘偏差误差的最重要参数是构建方向，而宽度方向不准确度、构建时间和构建分数在很大程度上受每单位激光能量的影响长度。GR 分析表明构建方向是最重要的参数。这项研究对于在 LDED 期间考虑构建几何形状和构建经济性很重要。