Abstract
Single-track laser melting experiments were performed on bulk Ti-Nb alloys to explore process parameters and the resultant macroscopic structure and microstructure. The microstructures in Ti-20Nb and Ti-50Nb (at.%) alloys exhibited cellular growth during rapid solidification, with average cell size of approximately 0.5 µm. Solidification velocities during cellular growth were calculated from images of melt tracks. Measurements of the composition in the cellular and intercellular regions revealed nonequilibrium partitioning and its dependence on velocity during rapid solidification. Experimental results were used to benchmark a phase-field model to describe rapid solidification under conditions relevant to additive manufacturing.
Original language | English |
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Pages (from-to) | 1589-1597 |
Number of pages | 9 |
Journal | JOM |
Volume | 70 |
Issue number | 8 |
DOIs | |
State | Published - Aug 1 2018 |
Funding
This work was performed under the auspices of the U.S. Department of Energy (DOE) by Lawrence Livermore National Laboratory under Contract No. DE-AC52-07NA27344. Work was supported by the Laboratory Directed Research and Development (LDRD) Program under project tracking Code 18-SI-003. TEM work was performed at the Colorado School of Mines and was supported by A.J.C.’s Early Career Award from the U.S. DOE, Office of Science, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, Award No. DE-SC0016061. J.-L.F. acknowledges support from the Exascale Computing Project (17-SC-20-SC), a collaborative effort of the U.S. DOE, Office of Science, and the National Nuclear Security Administration. The authors thank Nick Teslich at LLNL for his impeccable work on the FIB specimen preparation for TEM and John Mangum at CSM for his help with the NanoMill ®.