Scientists from the Australian Nuclear Science and Technology Organisation (ANSTO) are working with Australian industry to design an instrument that will take materials testing to the ultimate level, allowing analysis of atomic structures.
This instrument will have particular application for stress testing components of major engineering projects. Now on the drawing board, the Residual Stress Diffractometer (RSD) is one of eight instruments being designed to take full advantage of the probing qualities of neutrons produced by the Replacement Research Reactor being constructed at Lucas Heights.
This new capability will complement existing techniques for testing materials in the workshop, but means that scientists will gain an understanding of how materials work at the atomic level, using a technique known as strain scanning.
Forty-seven representatives of science and industry met at the University of NSW recently to discuss and provide input for the design of the RSD and the other instruments to be attached to the Replacement Research Reactor.
Leading the effort to design the RSD from ANSTO is Dr Oliver Kirstein, who recently moved to Australia from Germany after designing the high-resolution backscattering spectrometer for the FRM-II research reactor in Munich.
"There are many stress-related problems in a wide variety of fields in Australia, such as the manufacturing industries, mining, oil and gas, and rail transport industries," Dr Kirstein said.
"The biggest advantage of using neutrons is that they can penetrate deep into material in a way that is non-destructive. Strain scanning provides another tool for solving problems to complement facilities at the major research institutes."
Residual strains occur when components contain different physical properties. More specifically, stresses occur when some part of the sample deforms plastically (meaning it will not return to its original shape) while an adjacent part deforms elastically (meaning it returns to its shape when any deforming force is removed). This is of interest, for example, to the welding industry, where the weld metal deforms plastically and constraining parts deform elastically meaning that the range of materials that can be welded to high specifications is restricted.
Forming technologies, such as casting and forging, often involve residual stresses because of uneven temperatures that are applied to the material. Strain scanning provides the means to measure stress and texture at depth so that strategies can be formed to prevent distortions when castings and forgings are machined to finished parts. The researchers believe that processing of magnesium castings an activity widely carried out in Australia has particular promise for strain scanning because of the favourable neutron properties of the material.
The new instrument will also be useful for formulating life extension strategies of materials, to provide knowledge that can have considerable economic impact for industries.