【作者】 陶友瑞；

【导师】 张福全； 陈振华；

【作者基本信息】 湖南大学 ， 材料加工工程， 2004， 硕士

【摘要】 耐热铝合金(FVS0812)在423K至623K的温度范围内具有优良的力学性能因而受到广泛关注。本文对耐热铝合金(FVS0812)薄板半球形零件的拉深成形理论及工艺进行了研究。 采用喷射沉积一轧制工艺制备FVS0812薄板。FVS0812板的冲压成形性测定结果显示：板材具有较小的延伸率和塑性应变比，较大的屈强比，因此FVS0812板的拉深成形性能差。此外，零件的相对厚度仅为0.2％且形状复杂、冲压过程中零件的加热和保温困难使得FVS0812薄板半球形零件的拉深成形困难。 针对上述问题本文作者提出了一种新的拉深成形工艺，取名为包覆拉深，包覆拉深特点在于：将坯料夹于两块厚度大、强度高、塑性好的板料之间，使三块板料一起冲压成形。包覆板料的厚度大可以防止皱曲的产生，由于“摩擦保持效果”及“零摩擦效果”使得板料的变形均匀分散，极大地提高板料的冲压成形性能，在温拉深或者热拉深中包覆板料对于冲压件板料的保温作用也很明显，实验表明包覆拉深是一种行之有效的方法。 本文在Hill分叉点失稳的能量法则的基础上建立了半球形零件拉深成形的皱曲模型，该模型是分析内皱及外皱的理论依据。利用板壳理论中板屈曲的能量法建立了半球形零件冲压成形防内皱压边力模型，通过该模型可以计算出半球形件冲压成形防内皱压边力。依据所建立的压边力模型，设计了单动油压机的压边力调节装置，实验证明该装置对于防止内皱有重要意义。 作者以所建立的模型为理论基础，采用包覆拉深工艺拉深成形耐热铝合金(FVS0812)薄板半球形零件获得了成功。更多还原

【Abstract】 The heat-resistant Al-Fe-V-Si alloy (FVS0812) has drawn wide attention due to its excellent high-temperature properties over the range of 423K to 623K on a specific strength basis. In the present study, the forming theory and technology of the FVS0812 sheet as hemisphere-shaped workpiece were investigated.The FVS0812 sheet was prepared by spray deposition- rolling process. The tests on the drawing-ability of the sheet showed that the coefficient of elongation and plastic strain ratio were low and yield ratio .was high, which meant that the drawing-ability of FVS0812 sheet was bad. At the same time, there were other factors which made the drawing of FVS0812 hemisphere-shaped workpiece a difficult task, such as a low relative-thickness coefficient about 0.2%, a complex shape of the product and the difficulty in maintenance of an uniform temperature in workpiece during drawing.The author developed a novel drawing technology named as "packed -layer drawing" The characteristics of packed - drawing technology lay in that the FVS0812 sheet was coated by two layers of thicker metal sheets with high strength, good elongation. The three-layer sheets were darwed together. The thicker packing sheets could prevent wrinkling of FVS0812 sheet. The drawing-ability of FVS0812 sheet was improved greatly by "the effect of friction preservation" and "the effect of zero frictional resistance" which made the deformation in sheet scattered uniformly. Moreover, the packed sheets could reduce the heat loss of FVS0812 sheet in warm drawing or heat drawing. Experiences showed "packed -layer drawing" was a successful method in drawing of FVS0812 sheet.The winkling model in the process of drawing was developed on the base of Hill’s bifurcation-point bulking theory, which became the theoretical basis of the analysis of flange wrinkle and side-wall wrinkle. In addition, a critical side-wall wrinkle BHF(blank holding force) model of the hemispherical workpieces in the drawing process was established on the basis of the energy method in the shell theory. Critical side-wall wrinkle BHF of hemispherical workpieces during the drawing process could be calculated according to this model. An apparatus to adjust BHF on single-acting hydromechanical press was designed by the author based on the BHF model Experimental results showed that this device was useful in avoiding wrinkling during drawing.Based on the winkling model and the BHF model the FVS0812 sheet as hemisphere-shaped workpiece was drew successfully by "packed -layer drawing".更多还原