2024 Annual International Solid Freeform Fabrication Symposium (SFF Symp 2024): Process Development: Hybrid Manufacturing
Program Organizers: Joseph Beaman, University of Texas at Austin
Wednesday 8:00 AM
August 14, 2024
Room: Salon F
Location: Hilton Austin
Session Chair: Zhenghui Sha, University of Texas at Austin
8:00 AM
Development of a Large-scale Hybrid Manufacturing Platform for Advanced Toolpath and Parametric Control: Jakob Hamilton1; Walter Glockner1; Peyton Weisbeck1; 1Iowa State University
A hybrid manufacturing testbed is developed and presented as a case study for considerations in designing convergent manufacturing processes. Hybrid manufacturing, in its most popular form, combines the unique design and repair capabilities of directed energy deposition (DED) with the dimensional accuracy and excellent surface finishes of CNC machining. As DED technologies advance, there is a significant need for integrated toolpath and parameter control schemes, deviating from the prescriptive control in g-code based controllers. This work explores the design considerations in developing a custom hybrid manufacturing robotic testbed for near-unlimited motion and peripheral control. The system is generalizable to any localized manufacturing process; however, development is specifically presented toward pellet extrusion additive, wire-laser DED additive, and milling. The testbed fills a growing need in advanced control schemes and sensor integration within hybrid manufacturing, unlocking the combined benefits of additive and subtractive processes.
8:20 AM
Hybrid Additive Manufacturing of Technical Ceramics: Robert Kay1; Daniel Davie1; Louis Masters1; Matthew Shuttleworth1; 1University of Leeds
Conventional methods of ceramic manufacturing impose design constraints on the geometric complexity of parts. Recent attention has focused on using Additive Manufacturing processes to overcome this limitation. However, barriers remain that limit the industrial adoption of 3D printed ceramics including process speed, cost, range of processable materials, porosity, and part shrinkage. A hybrid manufacturing approach that combines additive, subtractive and interlayer drying processes in a single platform has been developed to overcome these restrictions. This approach has been demonstrated with an alumina paste using materials developed for extrusion and injection moulding methods. Since a wide range of ceramic materials can be formulated into shear-thinning pastes they can be readily processed using this approach without the need to extensively optimise the material’s rheological properties, particle size or incorporate photosensitive compounds. The ceramic components demonstrated sintered densities in excess of 99.7% across a wide range of geometrically complex demonstrators.
8:40 AM
Process Development and Control for Sensor-informed Hybrid-Additive Manufacturing: Dan Davie1; Louis Masters1; Matthew Shuttleworth1; Jaemin Lee1; Robert Kay1; 1University of Leeds
Hybrid-Additive Manufacturing (hybrid-AM) systems enable production of high-quality components by leveraging the advantages of multiple distinct process in a single manufacturing platform. However, novel process combinations create challenges for machine control due to the lack of machine-agnostic hybrid manufacturing software. This work presents improvements to a hybrid-AM platform for technical ceramics, incorporating multi-material extrusion (polymer filament and ceramic paste), infra-red drying, green machining, and multi-modal sensing. A bespoke software package was created to facilitate control of the distinct technologies and sensing operations using a single production file. Sensor data is used for process calibration and dynamic process parameter adjustment, increasing the systems intelligence. For example, layer height measurements using a laser profilometer are used to tune the paste extrusion parameters. This enables the integrated fabrication of ceramic components with ~ 0.1 mm precision, complex geometries and near theoretical density, creating new manufacturing opportunities in the technical ceramics market.
9:00 AM
Laser Tempering for Hybrid Additive Manufacturing: Shohom Bose-Bandyopadhyay1; Nicole Van Handel1; Joseph Fletcher1; Christopher Saldaņa1; Thomas Kurfess1; Kyle Saleeby1; 1Georgia Institute of Technology
Additively manufactured parts, particularly tool steels, often suffer from high hardness due to the extreme thermal gradients that arise during printing. In order to machine parts to a desired surface finish, heat treatment is often necessary. Laser-based machining is an established strategy for decreasing workpiece hardness and can be employed during or after machining processes. However, there is little research available on laser tempering additively manufactured parts. We propose a single-machine hybrid workflow where a powder blown directed energy deposition laser used to perform tempering. An initial feasibility test is presented wherein disks of H13 were printed and tempered with variable laser power, standoff distance, and exposure time, with softening of up to 55% HV observed. Preliminary microstructural analysis is presented and discussed as compared to conventional tempering in literature. Initial tests from thermal monitoring are also shared, with intention of future thermal modeling.
9:20 AM
Development of Universal Gating System Tool for Sand Casting Industry: Jake Officer1; Fred Vonda1; Ismail Fidan1; 1Tennessee Technological University
Proper gating systems can be the determining factor of whether a cast part has excellent quality, or defects present. This is why optimizing gate systems plays an important role in improving the quality of cast parts. Due to the lack of precision in gate creation methods, inconsistencies exist across different casting processes. This research aims to address this by developing a framework for the creation of a universal gating system. Through an analysis of various gate systems using Inspire Cast and examining cast yields with various gating systems, this study seeks to develop a universal gating tool to ensure consistent and efficient casts. The goals of this study include achieving optimal metal flow, minimizing defects, and enhancing yield. This universal gating system offers a standard approach to gate design, which leads to improved quality and efficiency, reductions in production costs, and enhancements in the quality of cast components.
9:40 AM
Thermographic Porosity Estimation by Monitoring Non-Uniformity of Intra-Layer Cooling During Hybrid Directed Energy Deposition: Mario Rodriguez-Parra1; Eric MacDonald1; Bharat Yelamanchi2; Jimena Morales1; Thomas Feldhousen3; Pedro Cortes2; Eric LaNeave1; Callan Herberger1; 1University of Texas at El Paso; 2Youngstown State University; 3Oak Ridge National Laboratory
Hybrid Directed Energy Deposition (DED) combines the strengths of additive and subtractive manufacturing for efficient material use and complex design capabilities. In hot wire laser deposition, wire feedstock offers cost and safety advantages over powder-based AM. However, porosity remains a challenge, potentially impacting mechanical properties. This study proposes a novel approach using thermal monitoring during fabrication to indirectly quantify porosity. By analyzing cooling rates and internal temperature contours, the computer vision algorithm aims to identify voids, demonstrating a positive correlation with CT scan porosity measurements.
10:00 AM
Embedding Sensor Components into Metal Parts via Additive Friction Stir Deposition: Henry Claesson1; Mark Pandol1; Luke Hagedorn1; Toan Truong2; Amirhossein Omidi Soroor2; Mohsen Taheri Andani2; Pablo Tarazaga2; Hang Yu1; Christopher Williams1; 1Virginia Tech; 2Texas A&M University
The layerwise approach of additive manufacturing processes (AM) provides an opportunity to fully embed sensing components into a priori designed internal cavities to enable direct fabrication of intelligent parts. While this has been demonstrated in polymer AM, this is rarely demonstrated in metal AM processes due to their extreme processing conditions (e.g., high temperatures, intense laser irradiation, molten metal, electric arcs, etc.). In this work, the authors demonstrate a novel hybrid Additive Friction Stir Deposition (AFSD) process that fully encapsulates sensor packages within metal components. To ensure sensor survival and sufficient repair of the embedding interfaces, in-situ process monitoring of tool temperature and down force provides insight into embedding design guidelines. The mechanical performance of the final instrumented and embedded component as well as the metallurgy of its stir interface is characterized. The methodology is used to fabricate a metal part capable of sensing strain and temperature.
10:20 AM Break
10:40 AM
Lights-Out Hybrid Additive-Subtractive Manufacturing of Ti-6Al-4V Using Laser Powder Bed Fusion: Tanner Brandl1; Josh Soost2; Tom Houle2; Maxwyll McConnell1; Boone Gray1; Joseph Turner1; 1University of Nebraska-Lincoln; 2Matsuura USA
Hybrid metal additive manufacturing (AM) was used to manufacture a Ti-6Al-4V component based on laser powder bed fusion (LPBF) and 3-axis milling. The component specifications could not be satisfied using conventional subtractive manufacturing. Hybrid manufacturing was employed to manufacture the nontrivial geometry with a high degree of accuracy and surface finish. Available manufacturing parameters were modified to accommodate the manufacturing conditions present within the build chamber that precluded the use of machining coolant. The machining steps were integrated every 6 to 12 additive layers. Component characterization was done using X-ray computed tomography, micro-hardness mapping, and surface roughness measurements to quantify the uniformity of the build with respect to build height. Ultimately, the complete component was manufactured multiple times sequentially without pauses or human intervention (i.e., lights-out). This analysis highlights the feasibility of hybrid manufacturing for Ti-6Al-4V components with complex geometry and provides a strong foundation for further research.