skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering

Authors:
; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1411822
Grant/Contract Number:
NE0008440
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Journal of Nuclear Materials
Additional Journal Information:
Journal Volume: 485; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-12-07 13:16:43; Journal ID: ISSN 0022-3115
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Scott, Spencer M., Yao, Tiankai, Lu, Fengyuan, Xin, Guoqing, Zhu, Weiguang, and Lian, Jie. Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering. Netherlands: N. p., 2017. Web. doi:10.1016/j.jnucmat.2017.01.005.
Scott, Spencer M., Yao, Tiankai, Lu, Fengyuan, Xin, Guoqing, Zhu, Weiguang, & Lian, Jie. Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering. Netherlands. doi:10.1016/j.jnucmat.2017.01.005.
Scott, Spencer M., Yao, Tiankai, Lu, Fengyuan, Xin, Guoqing, Zhu, Weiguang, and Lian, Jie. Wed . "Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering". Netherlands. doi:10.1016/j.jnucmat.2017.01.005.
@article{osti_1411822,
title = {Fabrication of lanthanum-doped thorium dioxide by high-energy ball milling and spark plasma sintering},
author = {Scott, Spencer M. and Yao, Tiankai and Lu, Fengyuan and Xin, Guoqing and Zhu, Weiguang and Lian, Jie},
abstractNote = {},
doi = {10.1016/j.jnucmat.2017.01.005},
journal = {Journal of Nuclear Materials},
number = C,
volume = 485,
place = {Netherlands},
year = {Wed Mar 01 00:00:00 EST 2017},
month = {Wed Mar 01 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.jnucmat.2017.01.005

Save / Share:
  • The effect of the addition of the rare earth element, lanthanum, on the sintering characteristics of ZrB{sub 2}-ZrC composites has been analyzed during a spark plasma sintering (SPS) process. Microscopic observation confirmed that lanthanum accelerated mass transport by the formation of the liquid phase between the particles induced by the spark plasma in the initial stage of the SPS process, and then these were recrystallized to form a lanthanum-containing secondary phase at the grain boundaries and at the grain boundary triple junctions. In spite of the strong covalent bonding characteristics of the ZrB{sub 2}-ZrC composite there are many well-developed dislocationmore » structures observed. The fracture toughness of the lanthanum-containing ZrB{sub 2}-ZrC is about 2.56 MPa m{sup 1/2}, which is comparable to that of the pure composite. Therefore, it is concluded that lanthanum is very effective as a sintering aid for the ZrB{sub 2}-ZrC composite without any degradation of the mechanical properties.« less
  • Nitrogen-doped graphene (N-G) catalyst emerges as one of the promising non-platinum group metal (non-PGM) catalysts with the advantages of low cost, high oxygen reduction reaction (ORR) activity, stability, and selectivity to replace expensive PGM catalysts in electrochemical systems. This research investigated nanoscale high energy wet (NHEW) ball milling for the synthesis of N-G catalysts to make conventional problems such as sintering or localized overheating issues negligible. The successful synthesis of N-G catalysts with comparable catalytic performance to 10 wt% Pt/C by using this method has been published. This paper focuses on understanding the effect of grinding speed and grinding timemore » on the particle size and chemical state of N-G catalysts through the physical and chemical characterization. The research result shows that (1) the final particle size, nitrogen doping percentage, and nitrogen bonding composition of synthesized N-G catalysts are predictable and controllable by adjusting the grinding time, the grinding speed, and other relative experimental parameters; (2) the final particle size of N-G catalysts could be estimated from the derived relation between the cracking energy density and the particle size of ground material in the NHEW ball milling process with specified experimental parameters; and (3) the chemical composition of N-G catalysts synthesized by NHEW ball milling is controllable by adjusting the grinding time and grinding speed.« less
  • We report the first study of the effect of high-energy mechanical deformation on amorphous iron-based metallic alloys. The structural changes happening in amorphous iron-based materials containing Co or Ni during mechanical deformation show that the structural stability of an amorphous alloy against a thermal and a mechanical process are not related. Therefore, the concept of a high local effective temperature during the milling process cannot be singled out as the only reason for the observed structural transformations.
  • The effects of processing variables on the tensile properties and ductile-to-brittle transition temperature (DBTT) of Cr + 4 vol percent ThO/sub 2/ alloys and of pure Cr produced by ball milling in hydrogen iodide were investigated. Hot rolled Cr + ThO/sub 2/ was stronger than either hot pressed Cr + ThO/sub 2/ or pure Cr at temperatures up to 1540/sup 0/C. Hot pressed Cr + ThO/sub 2/ had a DBTT of 500/sup 0/C as compared with -8 to 24/sup 0/C for the hot rolled Cr + ThO/sub 2/ and with 140/sup 0/C for pure Cr. It is postulated that themore » dispersoid in the hot rolled alloys lowers the DBTT by inhibiting recovery and recrystallization of the strained structure.« less
  • The solid state reactions and the microstructural evolution during high-energy ball milling of Al-Ni powder mixtures in the composition rate 25--75 at.% Al have been investigated. Experimental observations have shown that the microscopic mechanism underlying the alloying process in this system is the diffusion of Ni atoms in the Al-rich layers and that an important role is played by the oxygen contamination. An amorphous Al-rich phase containing a few at.% oxygen and with a Ni content not exceeding approximately 50 at.% has been detected in the equiatomic and Ni-rich samples milled for a few hours. This phase upon further millingmore » transforms to a Ni-rich fcc solid solution thus allowing one to by-pass the nucleation of Al{sub 3}Ni in these samples. The self-sustaining high-temperature synthesis of the AlNi B2 phase has been found to occur over the 40--60 at.% range of Al concentration after about 3 h of milling. The same reaction has been observed in the Differential Scanning Calorimeter if equiatomic samples premilled for about 3 h (unreacted) are heated at a sufficiently high heating rate.« less