Directed Energy Deposition Additive Manufacturing (AM) Functionally Graded Material (FGM) Components

Creating components with metal alloys on a continuum rather than on a discrete basis will open design possibilities, improve performance, and enable the production of optimized, multifunctional metal parts for applications across key industries such as defense, aerospace, and energy. While metal additive manufacturing techniques such as Directed Energy Deposition (DED) has enabled functionally graded material (FGM) and multi-material printing, the ability to print with multiple materials in a single process presents significant challenges that will be addressed in the Phase II scope for this project. These key challenges include the following: 1. Material Factors: Different materials  have different melting temperatures, laser absorption, flowability, and chemical properties, making it challenging to determine process parameters that enable processing 2 or materials simultaneously without causing issues such as porosity, inconsistent bead geometry, and material compatibility (such as brittle intermetallic phases). 2. Material Switching: Switching between different materials and/or running 2 or more materials simultaneously during the printing process requires special consideration to obtain the desirable material composition in the melt pool and to minimize or prevent material cross-contamination between the various materials. 3. Print Process Quality Control: Achieving control and repeatability over the deposition of multiple materials can be challenging. Monitoring and validating the  process parameters, melt pool characteristics, powder flow characteristics, and machine configuration requires robust data logging, well-defined operator workflow, and robust process monitoring and control capabilities. 4. Software and Build Preparation: Multi-material components require manual programming and/or specialized software tools to command the machine “when and where” the material transitions or gradients shall occur within the program  Additionally, designing and preparing CAD models for multi-material printing can be more time-consuming and challenging than single-material printing 5. Testing/Qualification: The ability to test and qualify additively manufactured parts of a single material remains challenging, and the addition of more materials will require new inspection methods, multi-material characterization capabilities and databases, and  access to print process data to reduce performance risk, costs, and schedule. Addressing these challenges requires advancements in hardware, software, process development, and inspection capabilities to enable more efficient and reliable multi-material and FGM capabilities. In doing so, future high-value components can be built to fulfill location-dependent performance requirements by utilizing material on a continuum vs. discrete basis.