【正文】 onics industry, such as cellular phones and notebook cases. Although the prevailing manufacturing process of magnesium alloy products has been die casting, the stamping of magnesium alloy sheet has drawn interests from industry because of its petitive productivity and performance in the effective production of thinwalled structural ponents. As for stamping process, AZ31 magnesium alloy (aluminum 3%, zinc 1%) sheet has been monly used for the forming process at the present time, even though it needs to be formed at elevated temperature due to its hexagonal closedpacked (HCP) crystal structure ( [Chen et al., 2020] and [Chen and Huang, 2020]). Recently, the magnesium–lithium (LZ) alloy has also been successfully developed to improve the formability of magnesium alloy at room temperature. The ductility of magnesium alloy can be improved with the addition of lithium that develops the formation of body centeredcubic (BCC) crystal structure ( [Takuda et al., 1999a], [Takuda et al., 1999b] and [Drozd et al., 2020]). In the present study, the stamping process of a notebook top cover case with the use of LZ sheet was examined. The forming of the two hinges in the top cover of a notebook, as shown in Fig. 1(a and b), is the most difficult operation in the stamping process due to the small distance between the flanges and the small corner radii at the flanges, as displayed in Fig. 1(c). This geometric plexity was caused by a dramatic change in the corner radius when the flange of hinge gets too close to the edge of the 8 notebook, which would easily cause fracture defect around the flange of hinge and require a multioperation stamping process to overe this problem. In the present study, the formability of LZ magnesium alloy sheets was investigated and an optimum multioperation stamping process was developed to reduce the number of operational procedures using both the experimental approach and the finite element analysis. Fig. 1. Flange of hinges at notebook top cover case. (a) Hinge, (b) top cover case and (c) flanges of hinge. View thumbnail images 2. Mechanical properties of magnesium alloy sheets The tensile tests were performed for magnesium–lithium alloy sheets of LZ61 (lithium 6%, zinc 1%), LZ91, and LZ101 at room temperature to pare their mechanical properties to those of AZ31 sheets at elevated temperatures. Fig. 2(a) shows the stress–strain relations of LZ sheets at room temperature and those of AZ31 sheets at both room temperature and 200 176。 LZ91 板材在室溫成形性能優(yōu)越，也表明在目前的筆記本頂蓋制造的成功研究。四步操作過程的有限元分析的基礎(chǔ)上設(shè)計，然后由實驗數(shù)據(jù)證實。這是要注意，圖 5（ ac）只顯示一個鉸鏈的形成。第三步是開放的一面折疊，使側(cè)壁可以圍繞其周邊完成，如圖 5（ c）所示。此外，法蘭的高度符合要達到的目標。在當前的工業(yè)實踐中，形成頂蓋的情況下，使用鎂合金板材，通常需要至少十步的運作程序。采用有限元軟件 PAM_STAMP 進行分析，并在臺式電腦上進行模擬。出于這個原因，本研究采用 LZ91 板材的筆記本頂蓋的空白，并試圖探討在室溫成形性 LZ91。 2。 1999]， [Takuda 等。 關(guān)鍵字 ?筆記本電腦情況下 。 1 出處： Journal of Materials Processing Technology Volume 201, Issues 1–3, 26 May 2020, Pages 247–251 10th International Conference on Advances in Materials and Processing Technologies — AMPT 2020 題目： 筆記本頂蓋的鎂合金板材沖壓模具設(shè)計 ?蔡恒光，廖浩欽 ， 陳復(fù)國 摘要： 在本文章中，對 LZ91 鎂鋰合金板材在室溫下制造筆記本頂蓋時的沖壓工藝進行了檢查，同時使用了實驗方法和有限元分析。它提供了一個在電子行業(yè)替代鎂合金的應(yīng)用。鎂合金的延展性，可以改善鋰此外，開發(fā)形成體心立方（ BCC）晶體結(jié)構(gòu)（ [Takuda等人。 2 圖 1 在筆記本頂蓋的鉸鏈法蘭 （ a）鉸鏈，（ b）頂蓋情況和（ c）法蘭。 C 由于鋰的成本是非常昂貴，而不是 LZ101 板材 LZ91 板材，可被視為一個合適的 LZ鎂合金板材在室溫下呈現(xiàn)良好的成形性。在初始運行中使用的其他模擬參數(shù)為：沖壓力 5 毫米 /秒，壓邊力 3千牛，庫侖摩擦系數(shù)為 。 4. 多工序沖壓工藝設(shè)計 為了避免發(fā)生斷裂，多工序沖壓過程是必需的。這意味著可避免斷裂 缺 損。鉸鏈，從而形成，如圖 5（ b）所示。在最終產(chǎn)品的角落的最小厚度為 毫米，和所有株以上的成形極限圖。表 1 中可以看出，實驗數(shù)據(jù)和有限元計算結(jié)果是一致的。 C。 ? Multioperation stamping。dela o Deformation of behavior of Mg–Li–Al alloy o J. Mater. Compd., 378 (2020), pp. 192–195 o 4. o Takuda et al., 1999a o H. Takuda, T. Yoshii, N. Hatta o Finiteelement analysis of the formability of a magnesiumbased alloy AZ31 sheet o J. Mater. Process. Technol., 89/90 (1999), pp. 135–140 o 15 5. o Takuda et al., 1999b o H. Taku