使用自主研发的摩擦系数测试设备,测试了不同压力条件下6016铝合金板材的摩擦系数曲线.基于动态显式有限元法,对铝合金发动机罩内板进行冲压成形模拟仿真,计算了成形后零件的FLD图、厚度云图和应力云图等.结果表明,在冲压成形过程中,板料的移动速度先快速增大后急剧降低,随冲压时间不断变化.与固定的摩擦系数值相比,采用变摩擦系数模型计算得到的开裂和起皱量略高.试验结果表明,采用变摩擦系数值的仿真结果能更精确预测零件的成形缺陷.

建立了基于蚁群算法的激光表面淬火工艺参数神经网络优化系统.用神经网络建立激光表面淬火工艺参数与目标参数的非线性模型,借助蚁群算法搜索决策工艺参数的最优组合,自动优化工艺参数.用VC++6.0开发了激光表面淬火工艺参数优化程序.结果表明,基于蚁群算法的神经网络优化系统用于解决激光表面淬火工艺参数优化问题是可行且有效的.

In order to obtain the hardening depth that treated with laser surface hardening simply and immediately,the process of laser surface hardening was analyzed and an analytical equation was concluded based on the semi-infinite surface point heat thermal diffusion equation,at the same time the experiment was conducted and ideal results were obtained.The method is right and efficient verified by the experimental results under existing experimental conditions.

Laser transformation hardening of ductile cast iron QT600-3 was investigated experimentally.In the experiment,a CO2 laser unit was used.The experimental results show that great amounts of acicular martensite are obtained in the zone hardened with a fairly large laser beam diameter and consequentially low power density on the sample surface,under a lower scanning velocity of laser beam.The hardness of the hardened surface reaches up to 60 HRC,which is about 2.4 times as high as that of matrix.In addition,the microhardness of surface improves with increase of laser power and decrease of laser scanning velocity.The depth of hardened layer is up to 0.95 mm,and it decreases with increase of laser scanning velocity and increases a little with increase of laser power.

A 3-D numerical model of the temperature field for the laser transformation hardening was created based on finite element software ProCAST. The temperature field of the laser transformation hardening of ductile cast iron QT600-3 was calculated. According to the temperature field, the depths and widths of the hardened band were predicted. When the laser power ranged from 800 W to 1 000 W, the scan velocity ranged from 2.000 mm/s to 2.667 mm/s, and the diameter of laser beam ranged from 4 mm to 5 mm, The depths of the hardened distribute between 0.20 mm and 0.64 mm as well as the widths distribute between 2.0 mm and 3.7 mm. The depths and widths of the hardened band rises with increase in laser power or decrease in laser scanning velocity. It was found that the numerical simulated results wa