Additive Manufacturing of Metals: Additive Manufacturing - An Array of Processes
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
Thursday 8:00 AM
October 20, 2011
Room: D130
Location: Greater Columbus Convention Center
Session Chair: Suresh Babu, The Ohio State University
8:00 AM
Additive Manufacturing of Metals and AMC: Ian Harris1; 1EWI
Additive Manufacturing (AM) of metals is a rapidly growing field of research and development worldwide. Several processes have, and are being developed, but most are not yet qualified for production parts, especially in the aerospace and defence market where extensive, detailed material and process qualification is needed. The drivers to implement the AM processes are many and include foreshortening of the innovation timeline from design to part, elimination of expensive tooling associated with traditional manufacturing methods. Potentially large cost savings and sustainability improvements are possible, but not yet proven in many cases. The disruptive nature of AM processing presents a whole new vista of opportunities, economic and social. Realizing these benefits will take a lot of work, and collaboration in many of the key precompetitive building blocks makes sense to many. An Additive Manufactruing Comsortium (AMC) has been formed by 20 industrial members and partners to address these needs.
8:40 AM Student
Fabrication of Precipitation Strengthened Surface Layers via Additive Friction Stir Processing: Jeff Rodelas1; John Lippold1; 1The Ohio State University
Friction stir processing (FSP), a derivative friction stir welding, is a solid-state severe plastic deformation process used to locally modify microstructure and improve material properties/performance. Additional benefits and/or unique behavior can be obtained by incorporating additional materials during FSP. For predominantly low-Tm systems (e.g., Al- and Mg-base alloys) inert additions have been successfully incorporated via FSP to form MMCs. However, very little is known regarding the use of additive FSP to create location-specific surface alloying—especially for high Tm materials such as Ni-base alloys. Additive FSP was used to create a precipitation-hardened Ni-alloy surface layer on a non-precipitation strengthened workpiece (Inconel Alloy 600) without post-FSP heat treatment. Resultant surface layers exhibited microhardness values twice that of base Alloy 600. Strengthening precipitates were characterized using high-resolution SEM and TEM. Microstructural evolution of surface layers as a function of FSP process parameters will also be discussed.
9:00 AM
Gamma Titanium Aluminide with High Niobium Content Produced by Electron Beam Melting: Sara Biamino1; Mathieu Terner1; Andrea Penna2; Ulf Ackelid3; Silvia Sabbadini4; Paolo Fino1; Matteo Pavese1; Claudio Badini1; 1Politecnico di Torino; 2Avioprop; 3Arcam AB; 4Avio SpA
In recent years, Electron Beam Melting (EBM) has matured as an additive manufacturing technology for metal parts. EBM is in continuous use for series production of orthopedic implants in titanium since 2007 and more recently, gamma titanium aluminide (γ-TiAl) components for aeroengines have been successfully manufactured with EBM. γ-TiAl alloys have strong potential for aerospace applications due to their low density and high strength at elevated temperatures, but their use has previously been hampered by lack of effective manufacturing methods. Contemporary research on γ-TiAl is focused on improvement of the oxidation resistance and retention of the mechanical properties to higher temperatures by increasing the content of refractory elements such as niobium. In this work, we present the first results of γ-TiAl with high niobium content (Ti-46Al-2Cr-8Nb) produced by EBM. The microstructure, the residual porosity and the chemical composition have been investigated immediately after EBM and also after heat treatments.
9:20 AM
Optimal Processing of Aluminum Alloys Using the DMLS Technology: Dustin Lindley1; Ping Wang1; Steve Rengers1; 1Morris Aerospace
With wide application in a variety of industries, aluminum alloys have significant commercial potential for the production of replacement and optimized geometries by direct metal laser sintering (DMLS). In this study, the properties of two aluminum alloys, AlSi10Mg (EN AB-43000) and aluminum 6061, as produced in a modified EOS M270 machine are described. Some basic relationships between the global energy density of the laser scanning process and the mechanical and micro-structural properties are developed for these alloys. The effects of various physical process parameters (oxygen level, platform temperature, layer thickness) are studied. In addition, a number of post-build treatment options are evaluated. Initial results suggest that material property improvements may be possible using next generation machines with higher laser power.
9:40 AM Break
10:00 AM
Laser-Assisted Twin-Wire Arc Spray: Ondrej Racek1; Daniel Sordelet1; 1Caterpillar, Inc.
A novel process to deposit coatings for surface restoration, corrosion and wear resistance was investigated. Steel feedstock wires, AISI 1030, 1080, and 420, were processed using a twin-wire arc process coupled with a Nd:YAG continuous laser beam. The coatings were deposited onto as-machined steel surfaces without other roughening such as grit blasting. Although the adhesion strength of the initial specimens fell short of expectations relative to the traditional surface preparation methods, the study revealed a strong sensitivity of the adhesion strength to the process parameters. Therefore, further refinement of the process parameters is expected to yield adhesion strength at least equivalent to the traditional coating techniques. Additionally, it was shown that a through-thickness laser-treatment increased the coating hardness.
10:20 AM Panel Discussion
10:50 AM Concluding Comments