材料加工專業(yè)畢業(yè)設(shè)計-英文翻譯--在拉深件內(nèi)使用空氣壓提高鋁板的拉深極限比

1、1中文 中文 2701 字Deep Drawing With Internal Air-Pressing to Increase The Limit Drawing Ratio of Aluminum SheetYoung Hoon Moon*t, Yong Kee Kang, Jin Wook Park, Sung Rak GongEngineering Research Center for Net Shape and D

2、ie Manufacturing,Pusan National UniversityThe effects of internal air-pressing on deep draw ability are investigated in this study to increase the deep drawability of aluminum sheet. The conventional deep drawing process

3、 is limited to a certain limit drawing ratio(LDR) beyond which failure will occur. The intention of this work is to examine the possibilities of relaxing the above limitation through the deep drawing with internal air-pr

4、essing, aiming towards a process with an increased drawing ratio. The idea which may lead to this goal is the use of special punch that can exert high pressure on the internal surface of deforming sheet during the deep d

5、rawing process. Over the ranges of conditions investigated for AI-1050, the local strain concentration at punch nose radius area was decreased by internal air-pressing of punch, and the deep drawing with internal air-pre

6、ssing was proved to be very effective process for obtaining higher LDR.Keywords: Deep Drawing, Internal Air-Pressing, Limit Drawing Ratio(LDR), AI-10501. IntroductionAluminum alloy sheets are inferior in press formabilit

7、y compared to the mild steel sheets. Most of the aluminum alloys have an r-value(plastic anisotropy value) between 0.7 and 1.0.Nonetheless, even though the r-values for the aluminum alloys are only about half 3This formi

8、ng limit depends, in addition to the shape change and process conditions, on the ability of a material to deform without failure.The 'limiting drawing ratio'(LOR), is commonly used to provide a measure of the dra

9、wability of sheet metal, being the ratio of maximum blank diameter to punch diameter under the drawing limit without failure(Thomas and Dadras, 1981; Leu, 1997; Chen and Sowerby,1996). It is well recognized that a high p

10、lastic anisotropy value(r-value) clearly indicated a better drawability, by inducing a high resistance of a sheet to thinning. But there is no single material parameter which satisfactorily describes the drawing behavior

11、.In this work, the effect of internal pressing on the formability of aluminum sheet is investigated to increase the LOR of aluminum alloys.Figure 1 is a schematic of a cup die, showing the punch, die and blank holder, an

12、d a partially formed cup. The punch is on the down stroke and is just beginning to draw the sheet-metal blank into the die cavity. If the blank size has been chosen correctly, the metal will work harden sufficiently to o

13、vercome the combined strength of the remainder of the blank metal and friction between it and the blank holder and the part will be successfully made. However, if the blank is too large, the part will break when the tens

14、ile strength is exceeded. The first deformation of the blank occurs between the die radius and the punch-nose radius part, since this is the part that is not supported by friction with the tooling components. The metal i