(1. 哈爾濱工業(yè)大學(xué) 金屬精密熱加工國家級重點實驗室，哈爾濱 150001；
2. 哈爾濱工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，哈爾濱 150001)
摘 要: 由于彎曲效應(yīng)，中厚板拉深時厚度方向存在明顯應(yīng)力梯度，使其與薄板拉深變形有所不同。通過有限元數(shù)值模擬，研究中厚板拉深變形過程中不同階段板材厚度方向的徑向應(yīng)力分布規(guī)律，揭示凹模圓角大小對中厚板拉深變形徑向應(yīng)力的影響規(guī)律。對厚度4.5 mm的5A06鋁合金板材進(jìn)行不同凹模圓角條件下內(nèi)徑為450 mm筒形件拉深實驗研究。結(jié)果表明：中厚板拉深過程中最大徑向應(yīng)力位于直壁區(qū)與凹模圓角過渡處；且隨凹模圓角的增大，最大徑向應(yīng)力值逐漸減小；破裂缺陷發(fā)生在凹模圓角與直壁區(qū)過渡處，且隨凹模圓角增大，破裂延緩發(fā)生，極限拉深行程顯著提高，凹模相對圓角為12時的極限深度比相對圓角4.5時的提高了83%。
關(guān)鍵字: 5A06鋁合金；中厚板；筒形件拉深；徑向應(yīng)力
（1. National Key Laboratory of Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China;
2. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China）
Abstract:The deformation behavior of deep drawing of plate is different from that of sheet metal because of the obvious stress gradient along the thickness direction induced from bending effect. The finite element analyses were performed to investigate the radial stress during the plate deep drawing process，and the maximum radial stress and its location along die radius were observed, the effect of die radius on radial stress was discussed. An experiment was conducted on the deep drawing of 5A06 aluminum plate with thickness of 4.5 mm into the cups with diameter of 450 mm. The results show that the maximum radial stress generates at the transition area between the die radius and cylinder wall, and the fracture occurs at the same place. With increasing the die radius the maximum radial stress decreases. And cracks initiate at the transition area between the cylinder wall and die radius. The maximum radial stress decreases and the fracture is delayed when the die radius increases, as a result, the limited punch stroke at the relative die radius of 12 is improved by about 83% compared with that at the relative die radius of 4.5.
Key words: 5A06 aluminum alloy; plate; deep drawing; radial stress
