Two point incremental forming of a complicated shape with negative and positive dies

In this work, incremental sheet forming of a complicated shape is investigated experimentally. Two point incremental forming with negative and positive dies are employed for manufacturing of a complicated shape with positive and negative truncated cones. The material is aluminum alloy 3105 with a thickness of 1 mm. The effects of process parameters such as sequence of positive and negative forming processes, step depth (incremental depth) and rotational speed of the tool on the maximum achievable outer and inner heights for the proposed specimen are investigated. The selected ranges for the step depth and rotational speed are 0.2 mm - 0.6 mm and 0-1000 rpm, respectively. The results show that both maximum achievable outer and inner heights of the specimen are increased with change of Positive/Negative variant to Negative/Positive variant. Also, the results prove that both maximum achievable outer and inner heights are increased with decreasing in the step depth and increasing in the rotational speed of the tool. An optimum parameter combination (Negative/Positive, step depth = 0.2 mm and rotational speed = 1000 rpm) is obtained to get the both maximum achievable outer and inner heights using the signal to noise ratio analysis.