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Provides a new answer to the resource discovery problem, which arises because although the Internet makes it possible for users to retrieve enormous amounts of…
Provides a new answer to the resource discovery problem, which arises because although the Internet makes it possible for users to retrieve enormous amounts of information, it provides insufficient support for locating the specific information that is needed. ALIBI (Adaptive Location of Internetworked Bases of Information) is a new tool that succeeds in locating information without the use of centralized resource catalogs, navigation, or costly searching. Its powerful query‐based interface eliminates the need for the user to connect to one network site after another to find information or to wrestle with overloaded centralized catalogs and archives. This functionality was made possible by an assortment of significant new algorithms and techniques, including classification‐based query routing, fully distributed cooperative caching, and a query language that combines the practicality of Boolean logic with the expressive power of text retrieval. The resulting information system is capable of providing fully automatic resource discovery and retrieval access to a limitless variety of information bases.
There is recent emphasis on designing new materials and alloys specifically for metal additive manufacturing (AM) processes, in contrast to AM of existing alloys that were…
There is recent emphasis on designing new materials and alloys specifically for metal additive manufacturing (AM) processes, in contrast to AM of existing alloys that were developed for other traditional manufacturing methods involving considerably different physics. Process optimization to determine processing recipes for newly developed materials is expensive and time-consuming. The purpose of the current work is to use a systematic printability assessment framework developed by the co-authors to determine windows of processing parameters to print defect-free parts from a binary nickel-niobium alloy (NiNb5) using laser powder bed fusion (LPBF) metal AM.
The printability assessment framework integrates analytical thermal modeling, uncertainty quantification and experimental characterization to determine processing windows for NiNb5 in an accelerated fashion. Test coupons and mechanical test samples were fabricated on a ProX 200 commercial LPBF system. A series of density, microstructure and mechanical property characterization was conducted to validate the proposed framework.
Near fully-dense parts with more than 99% density were successfully printed using the proposed framework. Furthermore, the mechanical properties of as-printed parts showed low variability, good tensile strength of up to 662 MPa and tensile ductility 51% higher than what has been reported in the literature.
Although many literature studies investigate process optimization for metal AM, there is a lack of a systematic printability assessment framework to determine manufacturing process parameters for newly designed AM materials in an accelerated fashion. Moreover, the majority of existing process optimization approaches involve either time- and cost-intensive experimental campaigns or require the use of proprietary computational materials codes. Through the use of a readily accessible analytical thermal model coupled with statistical calibration and uncertainty quantification techniques, the proposed framework achieves both efficiency and accessibility to the user. Furthermore, this study demonstrates that following this framework results in printed parts with low degrees of variability in their mechanical properties.