TY - JOUR
T1 - Impact of W on structural evolution and diffusivity of Ni–W melts
T2 - an ab initio molecular dynamics study
AU - Wang, William Yi
AU - Shang, Shun Li
AU - Wang, Yi
AU - Fang, Hua Zhi
AU - Mathaudhu, Suveen N.
AU - Hui, Xi Dong
AU - Liu, Zi Kui
N1 - Funding Information:
This work was financially supported by the National Science Foundation (Grant No. DMR-1006557) and the Army Research Laboratory (W911NF-08-2-0064 and W911NF-09-2-0045) in the Unites States, National Natural Science Foundation of China (50431030 and 50871013), and National Basic Research Program of China (2007CB613901). W.Y. Wang acknowledges the support from the Project Based Personnel Exchange Program with American Academic Exchange Service and China Scholarship Council (2008[3072]). First-principles calculations were carried out on the LION clusters at the Pennsylvania State University supported by the Materials Simulation Center and the Research Computing and Cyberinfrastructure unit at the Pennsylvania State University. Calculations were also carried out on the CyberStar cluster funded by NSF through grant OCI-0821527 and the XSEDE cluster through grant TG-DMR-140033 and TG-DMR-140063.
Publisher Copyright:
© 2014, Springer Science+Business Media New York.
PY - 2015/2
Y1 - 2015/2
N2 - Abstract: Effects of W on structural evolution and diffusivity of Ni–10W and Ni–20W (at.%) melts are studied via ab initio molecular dynamic simulations. The atomic local topology is characterized in terms of pair correlation functions, structure factors, bond pairs, and topological structures. It is observed that the Ni–20W melt is more closely packed than the Ni–10W, showing higher average coordination number and more Voronoi polyhedra with high coordination numbers. The tracer diffusion coefficients of Ni and W calculated by the mean-squared displacement are very close to each other in both Ni–W alloys. Comparing with their self-diffusion coefficients of pure Ni and pure W, the tracer diffusion coefficient of Ni in Ni–W melts decreases, while that of W increases. Nearly identical tracer diffusivities of Ni and W in Ni–W melts attribute to the formation of local solute-centered polyhedra with high deformation electron density severing as bridges between various atomic clusters and strengthening the atomic bonding, indicating the collective motion of Ni and W in those melts. Moreover, atomic bonds of Ni–W metallic melts characterized by the deformation electron density present the network among different atomic clusters, revealing the physical nature of the collective motions between W and Ni.Graphical Abstract: [Figure not available: see fulltext.]
AB - Abstract: Effects of W on structural evolution and diffusivity of Ni–10W and Ni–20W (at.%) melts are studied via ab initio molecular dynamic simulations. The atomic local topology is characterized in terms of pair correlation functions, structure factors, bond pairs, and topological structures. It is observed that the Ni–20W melt is more closely packed than the Ni–10W, showing higher average coordination number and more Voronoi polyhedra with high coordination numbers. The tracer diffusion coefficients of Ni and W calculated by the mean-squared displacement are very close to each other in both Ni–W alloys. Comparing with their self-diffusion coefficients of pure Ni and pure W, the tracer diffusion coefficient of Ni in Ni–W melts decreases, while that of W increases. Nearly identical tracer diffusivities of Ni and W in Ni–W melts attribute to the formation of local solute-centered polyhedra with high deformation electron density severing as bridges between various atomic clusters and strengthening the atomic bonding, indicating the collective motion of Ni and W in those melts. Moreover, atomic bonds of Ni–W metallic melts characterized by the deformation electron density present the network among different atomic clusters, revealing the physical nature of the collective motions between W and Ni.Graphical Abstract: [Figure not available: see fulltext.]
UR - http://www.scopus.com/inward/record.url?scp=84919825352&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84919825352&partnerID=8YFLogxK
U2 - 10.1007/s10853-014-8664-7
DO - 10.1007/s10853-014-8664-7
M3 - Article
AN - SCOPUS:84919825352
VL - 50
SP - 1071
EP - 1081
JO - Journal of Materials Science
JF - Journal of Materials Science
SN - 0022-2461
IS - 3
ER -