基于BP-GA的大锻件过渡区宏观成形性能优化

针对铝合金大型锻件局部加载成形工艺下过渡区筋部充填不满的问题,借助于BP神经网络和GA遗传算法与数值模拟技术相结合的策略对锻件的局部加载成形工艺参数进行了研究。以锻件过渡区填充性作为质量评价目标,建立了坯料温度、压力机加载速度、第1道次压下量、进给量与质量指标之间的关系模型,利用遗传算法求解得到了合理的工艺参数:坯料温度为435℃,压力机加载速度为5 mm·s-1,第1道次压下量为18 mm,进给量为1165 mm,并将得到的工艺参数进行再模拟,并应用于生产试制,生产后的锻件筋部过渡区充填完整,对比模拟结果,表明所提出的策略能有效对大型锻件局部加载成形过渡区充填问题进行控制。     

Cooling slope casting to produce EN AW 6082 forging stock for manufacture of suspension components

The potential of cooling slope casting process to produce EN AW 6082 forging stock for the manufacture of EN AW 6082 suspension components was investigated. EN AW 6082 billets cast over a cooling plate offer a fine uniform structure that can be forged even without a separate homogenization treatment. This is made it possible by the limited superheat of the melt at the start of casting and the fractional solidification that occurs already on the cooling plate. Suspension parts forged from cast and homogenized billets with or without Cr all showed a uniform structure, and the hardness reached HV 110 after the standard artificial ageing treatment.     

注射成型技术进展

介绍了注射成型机、注射成型工艺的一些新进展，重点介绍了电动式注射成型机、预柱塞式注射成型机、往复式成型机、专用成型机等一些新式注射成型机；同时介绍了超高速注射成型、薄壁注射成型、复合注射成型工艺的特点。     

力反馈对中超精密球形转子研磨方法

为了获取高质量的超精密球体对四轴球体研磨机进行了改进。由于金属波纹管联轴器兼有传递运动、施加压力和导向功能，在机器的浮动轴结构中采用了这种联轴器。在研磨轴布置了压力传感器获取轴向压力信号，实现各轴压力的实时监测与控制。改进后可以使球体工件更好地对准理想中心，有效地减小了形状误差，而分级控制策略提高了自动化加工效率。磨削实验表明加工球体的表面质量得到较大提高。     

提高热连轧板板形质量的方法与措施

通过分析楔形、凸度、平直度等板形控制机理,结合莱钢热连轧工艺装备和板形质量特点,优化原始辊型、换辊周期、负荷分配等工艺,制定出与产品质量相关联的换辊制度、换辊模式、轧制计划安排等控制策略,改善了产品断面形状,板凸度由-20～250μm改善到30～70μm,板形异常卷控制在0.25%以下,薄规格比重提高到总产量的30%～40%。     

水质挥发酚检测质量控制的探讨

水质挥发酚检测过程质量控制是将分析误差控制在容许限度内,以保证检测结果在给定的置信水平内达到要求的质量.一组样品经过连续多日测试,将所得结果进行统计分析检查是否存在影响测试结果的系统误差,其目的是确定测试结果的精密度和正确度.     

双机热备方案探讨

目前自动化程度高,各单位对服务的安全性、可用性、依赖性变大。24小时不允许停机,在这种情况下,服务器的双机热备就显的非常必要及迫切。双机热备是近年来服务器端的安全性,可用性的一次重大的革命。从以前加大的硬件可用性,到现在的双机要备用,来保证服务器的不停机运行,是可用性的一次重大进步。     

沥青路面再生技术浅析

针对传统沥青路面养护方法工作量大、成本高、污染环境等弊端,介绍了国内外沥青路面再生技术的发展及应用,重点阐述了沥青路面再生技术的分类及与传统沥青路面养护方法相比所具有的技术经济优势,以期促进沥青路面再生技术的推广应用。     

2060-T8E30铝锂合金的热变形行为及本构模型研究

利用Sans CMT4104型电子万能实验机进行等温恒应变速率热拉伸试验,研究了2060-T8E30铝锂合金在变形温度425~500 ℃、应变速率0.001~0.1 s_^-1条件下的热变形行为。结果表明：2060-T8E30铝锂合金在热变形过程中,随着温度的升高和应变速率的降低,其峰值应力降低。合金的平均变形激活能为240.502 kJ/mol,平均应变速率敏感指数为0.28。基于热拉伸试验的真应力-真应变曲线,建立了具有应变补偿的Arrhenius本构方程,模型的预测值与实验值平均相对误差5.89%,模型的精确度较好。     

Microstructural evolution,flow stress and constitutive modeling of Al−1.88Mg−0.18Sc−0.084Er alloy during hot compression

To explore the hot compression behavior and microstructural evolution, fine-grained Al?1.88Mg?0.18Sc? 0.084Er (wt.%) aluminum alloy wires were fabricated with Castex (continuous casting?extrusion) and ECAP-Conform, and their hot compression behavior was investigated at temperatures of 673?793 K and strain rates of 0.001?10 s^?1; the microstructures were characterized by optical microscope, X-ray diffractometer, transmission electron microscope, and electron backscattered diffractometer, and the flow stresses were obtained by thermal compression simulator. Microstructural evolution and flow curves reveal that dynamic recovery is the dominant softening mechanism. Continuous dynamic recrystallization followed by dynamic grain growth takes place at a temperature of 773 K and a strain rate of 0.001 s^?1; the yielding drop phenomenon was discovered. Hyperbolic sine constitutive equation incorporating dislocation variables was presented, and a power law constitutive equation was established. The stress exponent is 3.262, and the activation energy for deformation is 154.465 kJ/mol, indicating that dislocation viscous glide is the dominant deformation mechanism.