Abstract
Directed energy deposition technologies for additive manufacturing such as laser selective melting (SLM) or electron beam melting (EBM) is a fast growing technique mainly due to its flexibility in product design. However, the process is a complex interaction of multi-physics on multiple length scales that are still not entirely understood. A particular challenging task are the flow characteristics of metallic powder ejected as jets from a nozzle and shielded by an inert turbulent gas flow. Therefore, the objective is to describe numerically the complex interaction between turbulent flow and powder grains. In order to include both several physical processes and length scales an Euler-Lagrange technology is applied. Within this framework powder is treated by the Discrete-Element-Method, while gas flow is described by Euler approaches as found in classical Computational Fluid Dynamics (CFD). The described method succeeded in delivering more accuracy and consistency than a standard approach based on the volume averaging technique and therefore, is suited for the solution of problems within an engineering framework.
Highlights
Additive manufacturing, known as 3D printing, processes synthesise a three- dimensional object by adding successive layers of materials under computer control [1] and is sometimes referred to as the third industrial revolution
The exchange of data between continuous and discrete solutions requires careful coordination and a complex feed-back loop so that the coupled analysis converges to an accurate solution. This is performed by coupling algorithms between the Discrete Element Method to Computational Fluid Dynamics (CFD) [11]
Contrary to a pure continuous approach, the current concept treats powder as a discrete entity, while the flow of carrier gas is described by classical Computational Fluid Dynamics (CFD)
Summary
Known as 3D printing, processes synthesise a three- dimensional object by adding successive layers of materials under computer control [1] and is sometimes referred to as the third industrial revolution. In its broad sense additive manufacturing includes processes such as binder jetting, directed energy deposition, material extrusion, material jetting, powder bed fusion, sheet lamination and vat photo-polymerisation that apply a variety of materials such as polymeric materials, biological materials, ceramic materials and metallic materials. Selective laser melting (SLM) and electron beam melting (EBM) apply metallic powders through one or several nozzles onto the substrate’s surface where the powder is fused layer by layer into the substrate through an energy input e.g. laser or electron beam. The entire environment is protected by a shielding gas due to the reactive atmosphere of the fusing particles. The powder interacts strongly with the the fluid dynamics of the shielding gas, that effects crucially the trajectory of single powder particles and its location of deposition. The objective of the current contribution is to describe numerically the complex process of powder deposition on a substrate
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
