Novel Processes for Advanced Manufacturing Summary of a Workshop (2013) / Chapter Skim
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4 Design of Materials - Session Summary
4 Design of Materials - Session Summary
Pages 39-53
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From page 39... ...
Murphy Professor of Materials Science and Engineering, Northwestern University; Chief Science Officer, QuesTek Innovations LLC Dr. Olson began his presentation by restating the goals of President Obama's Materials Genome Initiative, which was announced in June 2011: to expand the system of fundamental materials databases and cut materials development cycles in half or more.
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From page 40... ...
The successes in computational materials design helped the integrated computational materials engineering (ICME) process initiated by the DARPA-AIM program to gain acceptance, leading to a full optimization at the component level to predict design allowables and to put materials into use more rapidly.
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From page 41... ...
The model hierarchy integrates materials science, quantum mechanics, and applied mechanics. To get the maximum value out of the supporting database structure, the Thermo-Calc software is the central integrator of those systems.
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From page 42... ...
The difficulty of this project was that the data sets were very small -- large enough to determine the first and second moments of yield strength but not the shape of the distribution function. Researchers addressed this by using mechanistic Monte Carlo simulations to predict the shape of the distri bution function of yield strength, and they integrated sparse data through linear transformation.
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From page 43... ...
This will enable calibrated design tools to create new alloys optimized for the capabilities of the additive manufacturing process, particularly looking at alloys that can exploit faster solidification. He said that principles established in welding metal design can be adapted to additive manufacturing.
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From page 44... ...
In surface thermodynamics, techniques are almost always DFT-based, and the accuracy has been sufficient to achieve substantial gains in grain boundary cohesion for enhanced stress corro sion resistance. Another participant stated that in the last 15 years, six NRC reports have discussed the need for federal support for fundamental materials databases, but nothing is really taking place.
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From page 45... ...
It is a different paradigm compared to something like additive manufacturing in that steel manufacturing is a large-scale industry with severe cost constraints. Manufacturing issues often control the implementation of steel product research and development.
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From page 46... ...
He first described the Q&P process developed at the ASPPRC. First, the steel is heated into the austenitic phase field, and then it is quenched to form martensite.
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From page 47... ...
The hot stamping concept has been around for more than 20 years and is growing in importance in the automotive industry. The concept is as follows: rather than heat treating a formed component to a high-strength martensitic microstructure, a flat piece of sheet material is heated to the austenitic field, then formed and die quenched.
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From page 48... ...
He said that a challenging goal in materials design is to discover the links that can help explain materials behavior across critical length scales. This was a focus of the AIM program of DOD over a decade ago; Dr.
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From page 49... ...
He described multiscale modeling, which looks at different length scales and timescales, and where the interconnections and linkages between material structure, chemistry, and performance are not known. This becomes a network problem: Connections may be greater at higher length or timescales than at other places in the network, and a design process may be able to "leap" length scales or timescales because of how the information is networked together.
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From page 50... ...
In this case, Dr. Rajan explained that researchers developed a tolerance factor and then examined Curie temperature against the tolerance factor.
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From page 51... ...
Another participant noted that when the Human Genome Initiative started, it generated new experimental protocols to create new data; with the Materials Genome Project, the same type of new experimental protocols may be generated, causing a rapid expansion of fundamental databases. This could be the greatest impact of the project.
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From page 52... ...
Others defended the use of DFT calculations, saying that although improvements could always be made to the fidelity of the DFT calculations, in practice most are measured, not calculated. In general, the use of DFT does not appear to be a showstopper in the design process.
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From page 53... ...
Dr. Olson added that alloys have been developed for the current processing technology, so the opportunity exists to develop more robust materials.
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