Additive Manufacturing of Metals: Additive Manufacturing - General Session
Sponsored by: MS&T Organization
Program Organizers: Ian D. Harris, EWI; Ulf Ackelid, Arcam AB; Ola Harrysson, North Carolina State University; Sudarsanam Babu, The Ohio State University; Brent Stucker, University of Louisville
Monday 2:00 PM
October 17, 2011
Room: D130
Location: Greater Columbus Convention Center
Session Chair: Ian Harris, EWI
2:00 PM
Overview, History and Current Processes for Metal Additive Manufacturing: David Bourell1; 1University of Texas
While the earliest metals additive manufacturing (AM) processes trace to the early 1990s, precursor technologies in topography and photosculpture extend back over 150 years. Precursor AM processes arose in the mid-twentieth century. An explosion of AM innovation transpired over a ten year period from 1985-95. This history will be presented based on a survey of the United States patent literature. Metal AM will be placed in a broader context by reviewing the present landscape of all AM processes. Specific current AM processing techniques for metallic part production will be reviewed.
2:40 PM
Additive Manufacturing of Nickel-Base Superalloys: Comparing Electron Beam Melting and Laser Melting: Francisco Medina1; Krista Amato1; John Wooten2; Shane Collins3; Larry Murr1; Ulf Ackelid4; Ryan Wicker1; 1UTEP; 2CalRAM; 3Directed Manufacturing Inc; 4Arcam AB
Additive manufacturing is being developed to produce functional hardware without the use of tooling. Components can be built one layer at a time making the technology ideal for complex hardware where low volume or low-rate production is needed. For structural aerospace applications where low-rate production quantities are often the norm, nickel-base superalloys are used particularly in highly corrosive and high temperature applications. If the combination of layer building and nickel-base superalloys for aerospace applications can be successfully developed, then additive manufacturing will replace traditional methods of building such hardware. A study was undertaken to compare and contrast candidate additive manufacturing technology capable of producing nickel-base superalloys such as Electron Beam Melting and Laser Melting. Inconel 625 specimens were manufactured with both technologies. The comparison consisted of microstructural, tensile, and high temperature analysis before and after HIP. These results were compared to other techniques capable of producing alloy 625.
3:00 PM
Additive Manufacturing/Direct Digital Manufacturing: An Aerospace Perspective and Assessment of the Domestic Supply Base: Stephen Szaruga1; Howard Sizek1; Kevin Hartke2; Larry Dosser2; 1Air Force Research Laboratory; 2Mound Laser & Photonics Center
Additive Manufacturing and its subset, Direct Digital Manufacturing are innovative materials processing tools of great interest for the manufacture of aerospace components for Air Force applications. The Air Force Research Laboratory has been investing in additive manufacturing technology development for over a decade maturing processes for repair and fabrication of turbine engine and aircraft structural components. The promise of sustainable manufacturing processes based upon digital design data to produce net shape, precision components offers great promise to support the future environment of small quantity, tailorable component production runs. The Air Force also needs to understand the domestic capability to produce aircraft and engine components as well as assess the maturity of the supply chain to identify any areas of risk for future production.
3:20 PM Break
3:40 PM
Economic Model and Analysis of Cost Effectiveness of Rapid Manufacturing: Guha Prasanna Manogharan1; Ola Harrysson1; Richard Wysk1; 1NCSU
In recent years, there has been a paradigm shift in the application of Additive Manufacturing (AM) processes as a low volume production system. Improved capabilities of several metal-based processes have made AM, a viable method to produce complex biomedical and aerospace parts. Often, such high performance parts are made of expensive alloys and the solid freeform aspect of AM significantly reduces tooling, material cost and time. However, it is critical to study the economics of individual AM processes to better understand its relative cost effectiveness. In this study, three unique approaches: EBM (additive), CNC-RP (subtractive) and a hybrid process are studied. Part 'geometry-based' analysis in terms of part volume-convex hull volume ratio, aspect ratio, etc. is performed to correlate it with cost-performance of the processes. Results from this study will aid in the optimization of AM process selection and 'feature-selection' for individual processes in an integrated system.
4:00 PM
3D-Printing as Manufacturing Method: Thomas Studnitzky1; 1Fraunhofer
Conventional additive manufacturing methods for metal parts made huge efforts during the last years, but they do not allow a cost-effective manufacturing in large quantities. To overcome this restriction, Fraunhofer IFAM Dresden uses a modified screen printing process to manufacture 3-dimensional parts of complex shape and very high aspect ratios. For this purpose, a powder-binder mixture is printed layer-on-layer to the desired shape followed by a conventional sintering step. The advantage of this 3D-screen printing process lies in the possibility to manufacture complex designs including fine walls down to 50 µm and even hollow structures as well as good upscaling possibility for industrial purposes. Fraunhofer IFAM Dresden examined the suitability of this process for different metallic materials, such as steel, copper and MoSi2. The 3D screen printing process seems to be especially promising for making complex cellular structures, i.e. micro fluidic devices, heat exchangers or catalyst carriers.
4:20 PM
Additive Manufacturing of Metals: A Review: Edward Herderick1; 1EWI
Over the past 20 years, additive manufacturing (AM) has evolved from 3D printers used for rapid prototyping to sophisticated rapid manufacturing that can create parts directly without the use of tooling. AM technologies build near net shape components layer by layer using 3D model data. AM could revolutionize many sectors of manufacturing by reducing component lead time, material waste, energy usage, and carbon footprint. Furthermore, AM has the potential to enable novel product designs that could not be fabricated using conventional processes. This talk will present a review that assesses available AM technologies for direct metal fabrication. Included is an outline of the definition of AM, a review of the commercially available and under development technologies for direct metal fabrication, possibilities for reduction of greenhouse gas emissions, and an overall assessment of the state of the art. Perspective on future research opportunities will also be presented.
4:40 PM
Microstructure Control and Mechanical Properties Assessment of Additive Manufacture Ti6Al4V by TIG Welding Process: Fude Wang1; Stewart Williams1; 1Cranfield University
The microstructure of wire+TIG welding prcocess ALM Ti6Al4V has been systematically investigated in this research. It is found that the peak current/base current ratio and pulse frequency are found to have no significant effect on the refinement of prior beta grain of additive layer manufactured Ti6Al4V. However, the wire feed rate has a considerable effect on the prior beta grain refinement at a given heat input. This caused by extra wire input being able to supply many more heterogeneous nucleation sites and also results in a negative temperature gradient in the front of the liquidus which blocks the columnar growth and changes the columnar growth to equiaixal growth. Meanwhile TIG ALM large Ti6Al4V parts tensile, fatigue, fatigue crack growth rate and fracture toughness properties also have been investigated in this study.
5:00 PM
Microstructure, Wear and Corrosion Properties of Nickel-Based Carbide-Metal Matrix Composite Coating Formed by Direct Metal Laser Deposition: Samar Kalita1; 1University of North Dakota
Direct metal laser deposition (DMLD) was used to develop wear and corrosion resistant carbide-metal matrix composite coatings on AISI 1018 steel using a new powder blend of Ni-based, Cr3C2-based and WC12Co-based powders. Coating integrity was examined by optical microscopy, while the microstructure and composition were analyzed by SEM and EDS techniques. The corrosion properties were investigated in a NaCl solution using immersion testing and electrochemical techniques (OCP, potentiodynamic polarization, polarization resistance and Tafel analysis). Wear resistance was evaluated by Taber Abraser tests according to ASTM F1978-00e1. The morphologies of the worn surfaces and wear debris were analyzed by SEM and laser scanning microscopy. Coatings demonstrated significantly higher microhardness (650 HV) and wear resistance. Immersion test demonstrated that the coatings were very effective in resisting corrosion. No pits were observed on the composite clad after 21 days of immersion. The relationships between DLMD process variables and the coating characteristics were correlated.