【正文】 g of punch, and the deep drawing with internal airpressing was proved to be very effective process for obtaining higher LDR.Keywords: Deep Drawing, Internal AirPressing, Limit Drawing Ratio(LDR), AI10501. IntroductionAluminum alloy sheets are inferior in press formability pared to the mild steel sheets. Most of the aluminum alloys have an rvalue(plastic anisotropy value) between and , even though the rvalues for the aluminum alloys are only about half of steel(Roger, 1991), they show, under the right circumstances, quite satisfactory drawing behavior. Among the aluminum alloys some noticeable differences in forming behavior on the stamping shop floor have been observed(Roger, 1991。 Revised January 30, 2001)The design and control of a deep drawing process depends not only on the workpiece material, but also on the condition at the toolworkpiece interface, the mechanics of plastic deformation and the equipment used. The equipment and tooling parameters that affect the success or failure of a deep drawing operation are the punch and die radii, the punch and die clearance, the press speed, the lubrication and the type of restraint to metal flow(Hrivnak and Sobotoba, 1992。 Kawai et al., 1992。 Leu, 1997。39。對于超出1050號鋁的拉深極限，在拉深凸模內(nèi)通空氣壓以降低在凸模半徑范圍局部應(yīng)變以及使用內(nèi)部空氣壓獲得更高的拉深極限比是非常有效的方法的證明。Lange, 1985) because the relationship between the material, die design and test parameters, etc., versus the deep drawability may change with alloy systems. 大多數(shù)合金鋁有一個R值（塑性各向異性值）~。雖然通過一般的冶金和模具設(shè)計原則提高拉深性能，但在研究改善鋁板的成形性仍然不足。 Date and Padmanabhan, 1992。 Johnson and Mellor, 1983）對于可以從給定的材料已能判斷能否成功成形的幾何零件，知道該材料的成形極限是必要的。在這項工作中，研究內(nèi)部壓力對鋁板成形性能的影響，以提高鋁合金的的拉深極限比。如果板料的尺寸選擇正確，拉深將穩(wěn)定進行足以克服板料與壓邊的摩擦和部分綜合力，拉深將成功。 One possible way to do this is airpressing the internal surface of the blank by using specially designed punch. 一種可能的方式，這是空氣壓利用專門設(shè)計的沖床通氣在板料內(nèi)部表面的。實驗初步表明，板料直徑小于70mm都沒有發(fā)生破裂，因此我從70mm 直徑的板料逐步增加直徑，當破裂發(fā)生的板料時，實驗進行增加或減少板料的直徑，以確定材料的最大直徑來估算板料的拉深極限比。圖3示意本研究中使用的凸、凹模。因此根據(jù)板料的厚度，為凸、凹模選擇最合適的圓角半徑為6mm。在拉深前，板料涂上高潤滑油，以降低板料成形時的接觸摩擦。圖5顯示的是拉深的照片在給定的參數(shù)條件下拉深得到的。圖7顯示了空氣壓對拉深的影響載荷位移曲線，在一般情況下，板料的直徑大拉深力也增大，而這個數(shù)據(jù)表明了，在高空氣壓下，板料的直徑增大，拉深最大載荷并沒有一直增大，這就是說，內(nèi)部空氣壓有助于降低拉深力和板料摩擦力。4 結(jié)論空氣壓被證明是增加鋁1050拉深性能的有效方法。參考資料Chen X. and Sowerby R., 1996, Blank Development and the Prediction of Earing in Cup Drawing, International Journal of Mechanical Science, Vol. 8, , pp. 509516. Date . and Padmanabhan ., 1992, On the Prediction of the Forming Limit Diagram of Sheet Metals, International Journal of Mechanical Science, Vol. 34, , pp. 363374. Hrivnak A. and Sobotova L.,1992, The Influence of the Deformation Aging and the Conditions of Stress on the Properties of the Deep Drawing Steel Sheet, Journal of Materials Processing Technology, Vol. 34, pp. 425430.Johnson W. and Mellor .,1983 Engineering Plasticity, 2nd Ed., Ellis Horwood, Camelot Press, UK. Kawai N. et al., 1992,Friction Behavior in the Cup Ironing Process of Aluminum Sheets., Journal of Engineering for Industry, Vol. 114, ., 1997, Prediction of the Limiting Drawing Ratio and the Maximum Drawing Load in CupDrawing, International Journal of Machine Tools and Manufacture, Vol. 37, , pp. 201213. Lange K., 1985, Handbook of Metal Forming, McGrawHill, New York, pp. 2022. Roger P., 1991, Sheet Metal Forming, Adam Hilger, New York, pp. 181242. Thiruvarudehelvan S. and Loh ., 1993, Drawing of Cylindrical and Hemispherical Cups using an Improved Tooling for FrictionActuated Blank Holding, Journal of Materials Processing Technology, Vol. 37, pp. 267280. Thomas . and Dadras Jr. P., 1981, Modeling of Sheet Forming ProcessesAn Overview, Wright State Univ., Dayton, Ohio, pp. 122. Yossifon S. and Tisosh J., 1991, On the Dimensional Accuracy of Deep Drawing Products by Hydroforming Processes,” International Journal of Mechanical Science, Vol. 33, , pp. 279295.