Search

Laser Metal Deposition (LMD) is an additive manufacturing process that enables the production of complex structures on existing parts. To reduce the use of costly and energy-intensive produced materials like titanium, these structures can be selectively deposited on favorable but differing substrate materials. However due to differing material characteristics, this results in a high defect potential. Extensive process parameter development and online process monitoring helps to minimize the impact of defect formation. Monitoring of airborne acoustic process emissions can be used to identify critical defects early during the process and gain information about process stability. Two approaches for in-process time-frequency monitoring of the acquired acoustic data were compared within this work: The short time Fast Fourier Transformation and the Continuous Wavelet Transformation. Performance criteria based on detected distinct defect events were defined to evaluate both approaches and define specifications for an Acoustic Emission In-Process Monitoring system.

Additive manufacturing (AM) has been leveraged across various industries to potentially open design spaces allowing the design of parts to reduce the weight, cost, and integrated design. Over the past decade, AM has sped up fast enough to penetrate various industry offering potential solutions for multiple materials, such as metals, alloys, plastics, polymers, etc. However, challenges lie to best utilize the opened design spaces as current generation engineers are trained to design parts for the conventional manufacturing process. With this lack of design guidelines for the AM process, users are limiting themselves to best utilize the offering made by advanced manufacturing. For aerospace parts, the design freedom of additive manufacturing is attractive mainly for two purposes: for weight reduction through lighter, integrated design concepts as well as for functional optimization of parts aiming at an increase of performance, e.g., by optimizing flow paths. For both purposes, it is vital to understand the material-specific and manufacturing process design limits. In AM, combination of each material and manufacturing process defines the design space by influencing minimum thickness, angle, roughness, etc. This paper outlines a design guideline for the laser powder bed fusion (also DMLM, direct metal laser melting) AM process with Inconel 718 material. Inconel 718 is a superalloy with superior mechanical properties and corrosion resistance at elevated temperatures up to 700 °C and is, therefore, used in several applications including aerospace engine parts. Due to its weldability, the alloy has also been extensively investigated in laser powder bed fusion and other additive manufacturing processes. A comprehensive study is provided both analytically and experimentally suggesting how parts can be designed having critical design features, manufacturing direction/orientation to meet design requirements, design accuracy, and quality. Design features presented include walls, overhangs, bore holes, and teardrop shapes, with their minimal feature sizes and effects on accuracy and roughness of the build parts. For the light-weight design of parts, different concepts such as lattices and stiffener structures are discussed. For gas or liquid carrying flow channels, the geometrical form and size are highlighted. Based on an approach by Kranz et al., design guidelines for Inconel 718 are derived from the experiments and provided in the form of a catalog for easy application.

Additive Manufacturing (AM) is increasingly used in the industrial part production. More than almost any other manufacturing technology, AM embodies the fourth industrial revolution (Industry 4.0). Even though AM allows a nearly direct manufacturing of parts out of their CAD data, the order processing still requires a lot of manual work. This paper addresses this issue by presenting a cloud-based platform, which has the intension to integrate and automate the order processing for additively manufactured parts. In addition to facilitating the order processing of the manufacturing service provider, the platform also serves as an interface to the customer. The focus of the platform is on an automation of the order acceptance, the offer calculation, and the part screening for the identification of appropriate AM parts. The paper builds an exemplary Industry 4.0 showcase by illustrating concepts and methods for an automation of the order processing and introducing the architecture of the implemented system. This includes web-based services for the management of parts and orders as well as an integrated analysis of geometry data for checking of manufacturability and quotation costing. The evaluation examines the efficiency and effectiveness of the platform.

Broschüre des Forschungsschwerpunkts Maritime Systeme zur Forschungsausrichtung der beteiligten Institute., Brochure of the Research Cluster Maritime Systems on the research orientation of the participating institutes.