Forming micro channels on aluminum foils by using flexible die forming process

A flexible die forming process is proposed to form aluminum micro channels with channel widths not larger than 1 mm. Three micro channel dies and two different polyurethanes (40A and 90A) were used to form micro channels on the annealed and as-received aluminum foils (50 and 75 μm). For understanding the influences of size effects, polyurethane hardness and channel width on forming micro channels, a series of experiments were conducted. Through using different annealing conditions, different grain sizes were obtained such that different T/D, the ratio of thickness and average grain size, could be obtained. T/D ratio is used as a parameter to model the size effects in the two models proposed in this paper. These two models can predict the depths of the micro channels formed by the proposed process, so they can be used by industry as a design tool for product design, process design and development, annealing process, etc.