Investigation of Process-Structure-Properties-Relationships of graded Multi-Material-Components using Laser Directed-Energy Deposition
The progress in multi-material additive manufacturing (AM) has attracted a lot of attention in recent years. The primary incentive in this context is the demand for complex-shaped parts that offer a wide range of properties and enhanced functionalities. By applying the right material in the right spot, an improved performance can be achieved while optimizing the use of cost-intensive alloys. The ability to tailor material properties to specific regions of a part paves the way for a new era of efficiency, customization, and performance across various industries.
Similar to the varying degrees of industrial maturity among different metal-based AM processes, the progress in the development of additive multi-material processing varies as well. While multi-material applications manufactured by laser-based powder bed fusion (PBF-LB) are already under investigation, research in the realm of directed-energy deposition using laser beam (DED-LB) is still at an earlier stage. Apart from the different chemical and physical properties of the used materials, one key challenge in multi-material manufacturing using DED-LB lies in attaining comprehensive control over the complex two-phase flow composed of metal powder and carrier gas. Particle interactions, contamination, agglomeration effects, and clustering complicate the flow dynamics, leading to uneven particle dispersion within the powder gas stream. As a result, it remains challenging to entirely control the process and ensure a precise powder composition, especially in the case of graded transitions.
In this context, the project deeply investigates the underlying mechanisms and interdependencies of powder mixing and blending of two or more powders for the DED-LB process. Besides analyzing and monitoring the powder-gas stream using advanced sensor technology, further process control equipment will be installed to gain a comprehensive understanding of the processes during the manufacturing of multi-material parts. As multi-material parts contain additional challenges regarding process-structure-property relationships compared to single-material AM parts, a lot of effort is required for full-scope characterization. The project will determine relevant testing procedures addressing the characteristics of multi-material components, resulting in the development of tailored testing guidelines.
Key objectives:
Understanding the mechanism and relationships of powder mixing/ powder blending of two or more powders for DED-LB,
Overcome the process-related and microstructural challenges and enable the benefits of multi-material approaches by DED-LB using advanced sensor and measurement technology.
Create guidelines for powder blending, DED-LB of multi-material components, and testing of multi-material samples or components (e.g., close to service conditions) for both: AM of new components and using AM for modifications of semi-finished products.