Computer-aided engineering (CAE) simulation tools are being increasingly used in metals industry to speed up processing and manufacturing, where material data have been an integral part ever since such simulations were made possible. The traditional way of obtaining such data is through experimentation, which is expensive and time-consuming. It is therefore of no surprise that lack of material data has been a common problem in CAE simulation. Moreover, such practice has left materials design outside the optimisation loop of product design and manufacturing, which reduces the potential design space and may result in suboptimal end products. The ultimate solution to the problem above is to merge the materials design loop and the processing optimisation loop into one complete design space. The fundamental technical challenge here is the development of material models to calculate the properties that are essential for processing design and simulation.

An essential part of the material data for CAE simulation is the flow stress curves as a function of temperature and strain rate. The first part of the paper describes our recent work on modelling the flow stress curves of aluminium alloys. Two competing mechanisms for deformation, dominated by either dislocation glide or dislocation climb, were considered in the model, with automatic selection of the mechanism in operation. Extensive validation has been carried out and good agreement between calculated and experimental results has been achieved for a variety of aluminium alloys over a wide range of temperature and strain rate. The second part of the paper features a case study where the calculated material data, including physical, thermophysical properties and flow stress curves, have been integrated into a CAE package for the simulation of a hot forming process. The current status of integrating materials modelling with processing simulation is also discussed.