Thermomechanical Processing

Research in thermomechanical processing in the Department of Materials Engineering encompasses length scales from the macro to the nano, and processes from the conventional to the novel. Fields of endeavour include:

• Conventional metal processing research focused on the deformation behaviour of light alloys, including magnesium and titanium, supported by physical and computer simulation. Extruded magnesium alloys typically show a marked anisotropy of yield when comparing compression with tension, and the objective of this research is to quantify the microstructural and crystallographic factors which contribute to the anisotropy. The importance of this can be illustrated by imagining a car bumper made from magnesium or titanium. In an impact a bumper will typically have a tensile and a compression face, and in magnesium – unlike aluminium and steel - differential yielding will occur with the compressive face yielding first and a consequent shift in the neutral axis of the bumper. Quantification of the microstructural features is supported by synchrotron and neutron diffraction studies, and high resolution scanning electron microscopy.
• Novel non-isothermal heat treatment paths are being investigated as a means to improve the properties and reduce the energy input during the heat treatment of precipitate forming alloys. For example, retrogression and reaging of aluminium alloys is being pursued as a means to treat structures after repair.
• Equal channel angular processing (ECAP) is a deformation route by which large strains – typically in excess of true strains of 4 – can be imparted to a material with no change in cross section dimensions. Research at Monash focuses on optimising the processing of light alloys and steel via ECAP, and the subsequent characterisation and modelling of the microstructural refinement. The equipment developed at Monash is atypical in that it is able to impart a back-pressure to the billet during processing and consequently accelerate microstructural refinement.
• Microforming – where geometric length-scales approach microstructural length scales – is investigated as a means to produce components on the sub-millimetre scale without the need for extensive (and costly) machining.

Active Researchers in this field

Professor Yuri Estrin
Associate Professor Chris Davies
Dr Peter Thomson
Dr Christopher Hutchinson
Dr Rimma Lapovok