Neutron diffraction measurements of residual stress distribution in large zirconia based refractory bricks produced by electro-fusion and casting

Abstract

a b s t r a c tElectro-fusion and casting is used to produce large refractory bricks (∼250 kg) containing a high amount of ZrO 2 . These bricks are used in glass-making furnaces where good mechanical performance is required at very high temperatures (>1500• C). During the manufacturing procedure, they develop large residual stresses as a result of the cooling conditions and structural phase transformations they underwent. This leads to stress concentration and crack formation at different length scales. In order to characterize these phenomena, a 'multi-scale' analysis approach is under development, where different internal strain measurement methods are combined. In this approach we benefit from different gauge volumes provided by various diffraction methods, ranging from a few hundred nanometres to a few tens of millimetres. In the present paper, the results of neutron diffraction measurements on large ZrO 2 blocks are given. These results show the level of internal strains at the millimetre scale, based on (311) reflection of the monoclinic ZrO 2 . Overall, a range of 0.025% tensile to 0.1% compressive strain was observed. Clear strain gradients were also visible, as larger values in the interior of the block were encountered.

EBSD-assisted Laue microdiffraction for microstrain analysis

“…As a result of its processing history and the SPTs, the material contains high amounts of internal residual stresses which usually generate cracks and can cause early failure (Cockcroft et al, 1994;Patapy et al, 2009;Ö rs et al, 2017). There are three main causes of internal stress fields in the specimen.…”

Investigating Thermal Neutron and Gamma Ray Shielding Properties of Al Matrix Gd2O3-and W-Doped Composites Using Monte Carlo Simulations

“…Neutrons are used or emitted in nuclear power plants (during power generation and in fuel waste), particle accelerators, neutron imaging devices, elemental analysis and some biological applications [1][2][3][4][5][6]. Since neutrons have a net electric charge of zero, they do not enter into Coulomb interactions and interact with matter only at short distances (less than 1 fm) where the strong nuclear force is effective.…”