5A06铝合金锥形件挤压成形及数值模拟
发布时间：2018-10-09 14:02
【摘要】：随着社会经济的不断发展以及工业化程度的快速提高,铝合金已经被广泛的应用于航空、航天、船舶、建筑、桥梁等行业中,复杂的铝合金零件也得到了广泛的开发应用。相比于传统的铝合金制造工艺,冷挤压技术以其特有的成形精度高、综合性能好、节约成本等优点逐渐受到人们的关注。本文以5A06铝合金锥形件的冷挤压成形为研究对象,介绍了冷挤压的原理、金属流动规律及影响挤压的因素;利用UG三维造型软件对锥形件建模;计算和确定了冷挤压工艺中的相关参数。通过有限元理论以及DEFORM模拟软件分析了挤压过程中的速度、载荷、应力、应变以及成形规律,并通过实验分析了挤压过程中产品的力学性能以及显微组织变化,从而验证模拟结果的正确性。本论文的主要结论有:(1)采用四个工序挤压成形,锥形件成形状况良好,金属流线清晰均匀。随着凸模的压下,模头位置金属的流动速度逐渐减小,上部分的金属流动速度逐渐增加,中间位置金属的流动速度随着坯料尺寸的增加逐渐增大,在最后一次挤压的终了阶段,速度在中间位置达到最大,约30mm/s。挤压载荷均呈现规律性增大过程,其中第二次挤压初期模具需要较大的压力压入坯料,固初期载荷增加较快,随后稳定增加至最大值。挤压过程等效应力以及等效应变分布相对均匀,且变化趋势一致,挤压终了阶段最大等效应力值约为386MPa。(2)沿着成形件挤压方向,金属的变形量以及显微组织变形程度逐渐增大。底部型壁处金属变形程度最大,显微组织沿着挤压方向明显被拉长,呈现明显的纤维状;在挤压凸模未压入的成品件尾端,金属受到较大的挤压力作用,流线分布较为均匀,但是组织变形量相对较小。(3)对原材料进行热处理(310℃保温1小时,空冷),材料的抗拉强度和硬度降低,减小了变形抗力,增加了塑性以及原材料的可挤压性。对成形件进行显微硬度分析发现,在锥形件头部由于金属的变形量大,显微硬度值达到最高,平均为132.2HV,靠近挤压成型件的尾部,由于在挤压前进行了退火,在挤压过程中变形量较小,金属的显微硬度相对较低,平均为119.6HV。
[Abstract]:With the continuous development of social economy and the rapid improvement of industrialization, aluminum alloy has been widely used in aviation, aerospace, ships, buildings, bridges and other industries, the complex aluminum alloy parts have been widely developed and applied. Compared with the traditional aluminum alloy manufacturing process, cold extrusion technology has attracted more and more attention due to its high forming accuracy, good comprehensive properties and cost saving. In this paper, the cold extrusion forming of 5A06 aluminum alloy conical parts is studied, the principle of cold extrusion, metal flow law and factors affecting extrusion are introduced, and the conical parts are modeled by UG 3D modeling software. The relevant parameters in cold extrusion process are calculated and determined. The velocity, load, stress, strain and forming law of the extrusion process were analyzed by finite element theory and DEFORM software. The mechanical properties and microstructure changes of the products during extrusion were analyzed by experiments. The correctness of the simulation results is verified. The main conclusions of this paper are as follows: (1) the tapered parts are well formed and the metal streamline is clear and uniform. With the pressing of the punch, the flow velocity of the metal at the die head decreases gradually, the flow velocity of the metal in the upper part increases gradually, and the flow velocity of the metal in the middle position increases with the increase of the blank size, and at the end of the last extrusion stage, The speed is the highest in the middle position, about 30 mm / s. The extrusion load increases regularly, in which the die needs a large pressure to press into the blank at the beginning of the second extrusion, and the initial load increases rapidly, and then increases to the maximum value. The distribution of equivalent stress and strain during extrusion is relatively uniform, and the variation trend is the same. The maximum equal effect force at the end of extrusion is about 386MPa. (2) along the direction of extrusion, the amount of metal deformation and the degree of microstructure deformation increase gradually. The metal deformation at the bottom wall is the largest, the microstructure is obviously elongated along the extrusion direction, showing obvious fibrous shape, and at the end of the finished product which is not pressed into the extrusion punch, the metal is subjected to greater extrusion force, and the streamline distribution is more uniform. However, the amount of microstructure deformation is relatively small. (3) the tensile strength and hardness of the raw materials are reduced by heat treatment (310 鈩，
本文编号：2259609
[Abstract]:With the continuous development of social economy and the rapid improvement of industrialization, aluminum alloy has been widely used in aviation, aerospace, ships, buildings, bridges and other industries, the complex aluminum alloy parts have been widely developed and applied. Compared with the traditional aluminum alloy manufacturing process, cold extrusion technology has attracted more and more attention due to its high forming accuracy, good comprehensive properties and cost saving. In this paper, the cold extrusion forming of 5A06 aluminum alloy conical parts is studied, the principle of cold extrusion, metal flow law and factors affecting extrusion are introduced, and the conical parts are modeled by UG 3D modeling software. The relevant parameters in cold extrusion process are calculated and determined. The velocity, load, stress, strain and forming law of the extrusion process were analyzed by finite element theory and DEFORM software. The mechanical properties and microstructure changes of the products during extrusion were analyzed by experiments. The correctness of the simulation results is verified. The main conclusions of this paper are as follows: (1) the tapered parts are well formed and the metal streamline is clear and uniform. With the pressing of the punch, the flow velocity of the metal at the die head decreases gradually, the flow velocity of the metal in the upper part increases gradually, and the flow velocity of the metal in the middle position increases with the increase of the blank size, and at the end of the last extrusion stage, The speed is the highest in the middle position, about 30 mm / s. The extrusion load increases regularly, in which the die needs a large pressure to press into the blank at the beginning of the second extrusion, and the initial load increases rapidly, and then increases to the maximum value. The distribution of equivalent stress and strain during extrusion is relatively uniform, and the variation trend is the same. The maximum equal effect force at the end of extrusion is about 386MPa. (2) along the direction of extrusion, the amount of metal deformation and the degree of microstructure deformation increase gradually. The metal deformation at the bottom wall is the largest, the microstructure is obviously elongated along the extrusion direction, showing obvious fibrous shape, and at the end of the finished product which is not pressed into the extrusion punch, the metal is subjected to greater extrusion force, and the streamline distribution is more uniform. However, the amount of microstructure deformation is relatively small. (3) the tensile strength and hardness of the raw materials are reduced by heat treatment (310 鈩，
本文编号：2259609
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