﻿ 摩擦系数对5083铝合金热压缩试验变形行为影响的有限元模拟研究

摩擦系数对5083铝合金热压缩试验变形行为影响的有限元模拟研究Finite Element Simulation Study on the Effect of Friction Coefficient on the Deformation Behavior of 5083 Aluminum Alloy during Hot Compression Test

Abstract: The hot compression of 5083 aluminum alloy was carried out on thermal simulator. The effect of different friction coefficients 0, 0.2, 0.4 and 0.6 on the morphology, loading force, strain rate and strain distribution of 5083 aluminum alloy in thermal compression test was studied using finite element analysis software DEFOM-3D. The study shows that the contact friction coefficient has almost no effect on the load force, but the distribution of the strain rate and strain has a significant influence. With the increase of the contact friction coefficient, the deformation non-uniformity in-creases, the strain rate and the strain amount from both ends of the sample to the heart gradually increase, and the greater the coefficient of contact friction, the more pronounced the bulging phe-nomenon.

1. 引言

2. 试验方法

2.1. 试验材料与物理模拟

2.2. 有限元模型的建立

Figure 1. Finite element model of the hot compression sample

Φ10 × 15 mm，为减少计算量，选取圆柱体试样的1/2进行模拟运算；两端压头材料特征设定为刚性，压缩试样材料选用5083铝合金，材料流变应力曲线采用实测变形抗力曲线数据；试验过程中一端固定，另一端以恒定应变速率0.13 s−1沿Z向变形至50% (真应变0.69)；试样两端接触摩擦系数分别设置为0、0.2、0.4和0.6；模拟过程中试样整体温度设定为400℃，为了简化实验，使实验更具有针对性，热压缩过程中不考虑热传导的影响。

3. 试验结果与分析

3.1. 试样形态

3.2. 接触摩擦系数对应力–应变曲线的影响

3.3. 接触摩擦系数对应变速率的影响

(a) (b) (c) (d)

Figure 2. Thermal compression simulation results of specimens under different contact friction coefficients. (a) 0 s; (b) 0.5 s; (c) 1 s; (d) 1.5 s

Figure 3. Influence of different contact friction coefficient on load force

(a) (b) (c) (d)

Figure 4. The strain rate distribution of the specimen under different contact friction coefficients. (a) 0 s; (b) 0.5 s; (c) 1 s; (d) 1.5 s

3.4. 接触摩擦系数对应变的影响

(a) (b) (c) (d)

Figure 5. The strain distribution of the specimen under different contact friction coefficients. (a) 0 s; (b) 0.5 s; (c) 1 s; (d) 1.5 s

4. 分析与讨论

5. 结论

1) 5083铝合金热压缩时，随着接触摩擦系数的增加，变形不均匀性增强，鼓肚现象越明显。

2) 5083铝合金热压缩时，接触摩擦系数对载荷力影响不大，即润滑条件对应力–应变曲线的准确性没有显著影响。

3) 5083铝合金热压缩时，接触摩擦系数对应变速率和应变分布影响显著，从试样两端面到心部逐渐增大，且随着接触摩擦系数的增加，变形不均匀性增大，应变速率和应变分布差异更显著。

NOTES

*通讯作者。

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