Search

As the utilization of nuclear energy continues to expand, there is a growing focus on the development of lightweight and efficient nuclear shielding composites. In this paper, novel WB X /Al (x = 1, 2, 4) composites were designed based on shielding performance. The effects of reinforcement type, volume fraction, and material thickness on the 60Co and 137Cs γ-rays, fast and thermal neutron shielding performances were simulated. The results show that WB/Al composites offer better development potential compared to WB 2 /Al or WB 4 /Al composites. Additionally, a predictive model for the γ-ray shielding effectiveness of WB/Al composites, based on the areal density of tungsten, was proposed. The fabrication process involved mechanical ball milling and spark plasma sintering to fabricate 30 vol% WB/Al composites, with optimization of ball milling time, sintering temperature, and holding time. As a result, a novel nuclear radiation protection composite with uniform composition, a relative density of 97 %, and flexural strength of 527 MPa was acquired. [ABSTRACT FROM AUTHOR]

A fluorine-free route has been developed to fabricate V/Pr co-doped zircon (ZrSiO 4) ceramic pigments with Na 3 VO 4 and Pr(NO 3) 3 ·6H 2 O as colourants. The as-prepared pigments were characterized by XRD, Raman, XPS, UV–vis, FE-SEM, TEM and automatic colourimeters. The results show that Na 3 VO 4 can not only act as colourant to produce blue hue, but as mineralizer to accelerate the formation of V/Pr co-doped ZrSiO 4 pigment. A colour tuning between blue, green and yellow can be achieved by increasing the mole ratio of Pr/V, and the most intense yellow hue (L* = 74.55, a* = −0.38, b* = 46.82) is obtained at a mole ratio of Pr/V = 0.5. Both Pr4+ and Pr3+ cations are co-existed in the pigments, where Pr4+ contributes to the generation of yellow hue while Pr3+ undermines the yellow hue. The good chromatic ability in glaze at high temperature suggest its potential application in ceramic decoration. [ABSTRACT FROM AUTHOR]

Effects of cores types on non-solvent displacement nonaqueous precipitation synthesis of core-shell structured materials were investigated via taking case study on effects of carbon sources on C@ZrSiO 4 preparation. The influencing mechanism of carbon sources was investigated via XRD, FE-SEM, TEM and the CIELAB colorimeter. The results show that the optimized carbon source for non-solvent displacement nonaqueous precipitation synthesis of C@ZrSiO 4 is amorphous and isolated spheroid-like carbon source. Neither layer-structured particle nor sheet-like particle can be effectively encapsulated through non-solvent displacement nonaqueous precipitation method. The shell layer is difficult to be effectively encapsulated on the edges of the around of corresponding particle. In comparison with the higher crystallinity core, the amorphous core is more favorable for encapsulation. The core materials selection principles discovered in this work are expected to be widely referred in the preparation of other core-shell structural materials. [ABSTRACT FROM AUTHOR]

A novel (Li,Cr)–ZrSiO 4 jade green ceramic pigment was prepared using LiF as the mineralizer and synergistically enhanced charge-compensator. The effects of Cr/Si mole ratio on the synthesis and coloration of the pigment and the coloring mechanism were investigated via XRD, SEM, TEM, XPS, EPR, NMR, UV–Vis–NIR and CIELAB colorimetry. The results demonstrate that the charge-compensator promotes the synthesis of ZrSiO 4 , and more Cr enters into the zircon lattice. When the n(Cr)/n(Si) is 0.2, the pigments exhibit a jade green hue (L* = 75.74, a* = -7.37, b* = 5.18). The band of the (Li,Cr)–ZrSiO 4 pigments in the visible light region shifts towards positive wavelength (535 nm), which is closer to the center of the green light region. The novel pigments have excellent coloring performance stability while in a base glaze synthesized at 1200 °C and near-infrared reflectance in the range of 700–2500 nm. The co-doping of lithium balances bonding, thereby improving near-infrared performance, which shows broad development prospects in the field of ceramic applications and energy saving. [ABSTRACT FROM AUTHOR]