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Magnesium alloy shows good ductility and formability in a suitable temperature range, but the spinning of revolution surface workpiece with curved generatrix of magnesium alloy is a complicated problem; multi-pass spinning is low efficiency and needs multiple sets of die, and shear spinning is unsuitable for the formation of curved generatrix revolution surface since the strong thinning may lead to material damage. In this paper, one-pass hot spinning process for magnesium alloy AZ31 sheet is designed and investigated; the effect of the process parameters on the quality of the formed workpiece are analyzed; the minimal wall thickness and the maximal ovality of spun workpiece are taken as evaluating indexes; the process parameters are optimized by orthogonal experimental design based on the finite element simulation on the spinning process. The optimizing results of process parameters have been obtained: diameter-to-thickness ratio of sheet blank is 18, spinning temperature is 300 °C, feed rate is 1.0 mm/r, and swivel angle is 35°. Finally, the validity of the orthogonal experimental design results is demonstrated by one-pass hot spinning experiments. [ABSTRACT FROM AUTHOR]

This paper presents a statistical analysis of the performance of an Ytterbium fibre laser utilising single and dual gas jets in a single pass to blind cut dry pine wood. Cutting wood with lasers is a multi-factor process and a proper combination of the parameters involved is needed to achieve high quality and optimum process efficiency. This study employs design of experiments and statistical modelling approach to investigate the significant process parameters along with their interactions. A high brightness, 1 kW IPG single mode Ytterbium-doped fibre laser was employed to produce blind cuts on samples of dry pine wood. The experiments were performed parallel to the direction of the wood fibre. The parameters investigated include laser power, focal plane position, traverse speed, gas pressure and single and dual gas jets. Results were compared using a number of process responses which define the efficiency of the cut in terms of kerf depth, mass removal and energy consumption as well as quality of the cut section considering the heat-affected zone, kerf width and roughness of the edge of the surface. It has been found that application of an additional gas jet produced a surface finish superior to the single jet. [ABSTRACT FROM AUTHOR]