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This paper reports the design, making and characterisation of a series of Fe-based bulk metallic glass alloys with the aim of achieving the combined properties of high neutron absorption capability and sufficient glass forming ability. Synchrotron X-ray diffraction and pair distribution function methods were used to characterise the crystalline or amorphous states of the samples. Neutron transmission and macroscopic attenuation coefficients of the designed alloys were measured using energy resolved neutron imaging method and the very recently developed microchannel plate detector. The study found that the newly designed alloy (Fe48Cr15Mo14C15B6Gd2 with a glass forming ability of Ø5.8 mm) has the highest neutron absorption capability among all Fe-based bulk metallic glasses so far reported. It is a promising material for neutron shielding applications. [ABSTRACT FROM AUTHOR]

The magnetic and crystal structures of the series FexMn5-xSi3 (x=4,3.5,3,2,1) have been reinvestigated by neutron powder diffraction between 315 and 8 K. Fe atoms are found to preferentially occupy the 4d site of the hexagonal D88 structure (P63/mcm). The compound Fe4MnSi3 orders ferromagnetically below 300 K. Refinement of the neutron data for this compound indicates that the moments are aligned at ∼40° off the c axis. A high moment at the 6g site is due to a large Mn moment which is forced into a ferromagnetic alignment with the Fe moments. Associated with this moment is a moderate magnetic entropy change, with a maximum value of 4 J kg-1 K-1 for a magnetic field change of 5 T. The magnetic structure of Fe3.5Mn1.5Si3 is similar to that of Fe4MnSi3, but the Curie point is lower, below 240 K. A feature for this composition is the appearance of a spiral structure below 60 K. The compounds with x=1, 2, and 3 are all antiferromagnets with a spiral structure observed for Fe3Mn2Si3 at all temperatures up to the Néel point of 150 K. Two separate antiferromagnetic structures exist for Fe2Mn3Si3, one between 120 and 45 K and another structure for temperatures below 45 K. Similar features in the magnetic ordering are exhibited by FeMn4Si3. At temperatures between 70 and 95 K, the magnetic structure is similar to that of the low temperature phase of Fe2Mn3Si3. Accompanying the magnetic transition at 70 K is a structural distortion to space group Cmcm, a feature also observed for Mn5Si3. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Energy-resolved neutron transmission imaging is utilised for in situ comparisons of strain distributions in fastened assemblies with regular and self-locking Spiralock® female threads. The strain maps measured within torqued steel bolts indicate that for a Spiralock® thread, the load is distributed over a larger section of the fastener, making this type of thread more suitable for fastening of assemblies subject to transverse vibrations. [ABSTRACT FROM AUTHOR]