Additive manufacturing of metal matrix composite (MMC) is a challenging field to explore. Besides components’ geometric constitution, requirements related to final microstructures must be met. Depending on the application, such as tribology, machining, or magnetism related, there is a need to preserve a specific phase, which is generally responsible for the engineering function of the fabricated component. This work analyzes the laser power (P) parameter influence on track’s geometry and microstructure aspects of Fe and Sn-based alloy processed by directed energy deposition (DED). Objectives are observing the interaction between Fe-α and Sn-based alloy as a function of P and, then, define a processing window that allows the MMC microstructure. Experimental methodology relied on single-tracks bead-on-plate deposits with P variations. To assess track’s geometry and microstructure changes, postprocessing analyses were performed by scanning electron microscopy (SEM) and energy dispersive x-ray spectroscopy (EDS). Results show that P influences positively on tracks’ height, width, and cross section area. Greater laser power resulted in higher geometric aspects. Microstructure evolution was observed as P was enhanced from 150 to 700 W. In lower P ranges, Fe particles are not strongly affected by the heat source, resulting in an MMC microstructure mainly composed by Fe-α dispersed on a Sn-rich alloying matrix. When more thermal energy is provided due to higher laser power levels, Fe and Sn diffuse to a greater extent, resulting in an increased quantity of Fe-Sn phases and a more homogeneous microstructure. EDS mapping suggests that formed phases are Fe solid solutions containing Sn. Then, it is concluded that MMC microstructures are possible to be achieved around a P window of 150 W.

中文翻译：

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激光功率对定向能量沉积加工的 Fe 和 Sn 基合金轨道几何形状和微观结构方面的影响

金属基复合材料 (MMC) 的增材制造是一个具有挑战性的探索领域。除了组件的几何结构外，还必须满足与最终微观结构相关的要求。根据应用，例如摩擦学、机械加工或与磁性相关的应用，需要保留特定的相，这通常负责制造部件的工程功能。这项工作分析了激光功率 (P) 参数对通过定向能量沉积 (DED) 加工的 Fe 和 Sn 基合金的轨道几何形状和微观结构方面的影响。目标是观察 Fe-α 和 Sn 基合金之间作为 P 函数的相互作用，然后定义允许 MMC 微观结构的加工窗口。实验方法依赖于具有 P 变化的单轨道珠上板沉积物。为了评估轨道的几何形状和微观结构变化，通过扫描电子显微镜 (SEM) 和能量色散 X 射线光谱 (EDS) 进行后处理分析。结果表明，P 对轨道的高度、宽度和横截面积有积极的影响。更大的激光功率导致更高的几何方面。随着 P 从 150 W 增强到 700 W，观察到显微组织演变。在较低 P 范围内，Fe 颗粒不受热源的强烈影响，导致 MMC 显微结构主要由分散在富锡合金基体上的 Fe-α 组成。当由于更高的激光功率水平而提供更多的热能时，Fe 和 Sn 扩散到更大程度，导致 Fe-Sn 相的数量增加和更均匀的微观结构。EDS 映射表明形成的相是含有 Sn 的 Fe 固溶体。