冲孔参数对汽车用6014铝合金板材冲孔边部质量和扩孔率影响

Effect of punching parameters on punch edge quality and HET ratio of 6014 aluminum alloy sheet for automobile

采用不同的冲孔工艺参数对0.9 mm厚的6014铝合金板材冲孔,然后进行扩孔试验研究,分析了冲孔冲头圆角半径、冲头与凹模的不同相对单边间隙对冲孔边部质量和扩孔率的影响。结果表明:当冲头圆角半径为0.1 mm时,随着冲头与凹模间的相对单边间隙由13.9%增加到33.3%,板材冲孔边缘毛刺高度由13.3μm增加至152.1μm,板材冲孔边缘各个方向的光亮带占比变化差异不大,板材的扩孔率由60.5%降低至32.0%。当冲孔冲头与凹模的相对单边间隙为13.9%时,随着冲头圆角半径由0.1 mm增加至0.9 mm,板材冲孔边缘各个方向毛刺高度随冲头圆角半径变化不大,但板材冲孔边缘光亮带占比变化明显。当冲头圆角半径为0.1 mm、光亮带和撕裂带的临界线较平直时,光亮带占比为24%,扩孔率为60.5%;当冲头圆角半径由0.5 mm变为0.9 mm时,光亮带占比由30%左右降至10%以下,光亮带和撕裂带的交界线较曲折,板材的扩孔率由43.0%降低至40.8%。

The 6014 aluminum alloy sheet with thickness of 0.9 mm was punched by different punching parameters,and then the effects of the fillet radius of the punch and the different relative unilateral clearance between the punch and the die on the quality of the punch edge and the hole expansion ratios were analyzed.The results show that when the fillet radius of the punch is 0.1 mm,the burr height of the punching edge increases from 13.3 μm to 152.1 μm as the relative unilateral clearance between the punch and the die increases from 13.9% to 33.3%.The proportion of bright band in each direction of the punching edge has little difference,and the hole expansion ratio of the sheet decreases from 60.5% to 32.0%.When the relative unilateral clearance is 13.9%,as the fillet radius of the punch increases from 0.1 mm to 0.9 mm,the burr height in each direction of the punching edge of the sheet does not change much with the fillet radius of the punching edge,but the proportion of bright band changes obviously.When the fillet radius of the punch is 0.1 mm and the boundary between bright band and tear band is straight,the bright band ratio is 24% and the hole expansion ratio is 60.5%.When the fillet radius of the punch changes from 0.5 mm to 0.9 mm,the proportion of bright band decreases from about 30% to less than 10%,the intersection of bright band and tear band is tortuous,and the hole expansion ratio of the plate decreases from 43.0% to 40.8%.