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利用华铸CAE软件对大型挂舵臂铸钢件进行凝固过程的数值模拟,揭示了铸件产生缩松、缩孔的部位和形成原因。模拟结果表明:通过优化铸造工艺,合理设置冒口、冷铁,可以保证铸件的顺序凝固和金属液的有效补缩,获得结构完整、没有缺陷的铸件。 相似文献
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将振动技术应用于金属凝固过程,既能有效改善凝固组织、提高铸件的性能,还具有成本低、节能环保的优点,因此振动技术在金属凝固中的应用得到了广泛的实验研究。但由于金属熔体的高温和不透明性阻碍了对它的测量和观察,振动对凝固影响的机理尚不完全清楚。数值模拟能够提供振动条件下流场、温度场、应力场等各个参量的变化规律,有助于更全面地理解振动的作用机理。同时,振动对金属凝固影响的数值模拟还未得到系统研究。本文介绍了振动技术在金属凝固中应用的数值模拟的研究进展,在振动方式上主要包括超声振动、机械振动及脉冲电磁场的数值模拟,在应用内容上主要包括熔体处理、充型、凝固、除杂及时效过程的数值模拟。系统地介绍了振动技术在铸造过程的各方面应用的数值模拟原理和技术的研究现状,同时对未来研究方向进行了展望。 相似文献
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前言为了补充铸型中金属液在冷凝过程中发生体收缩,必须在铸件最后凝固部位设置冒口,同时,冒口本身储存足够金属液并最后凝固才能满足对铸件的补缩作用。众所周知,影响冒口补缩效果的因素很多,如:金属成份、浇注速度、浇注时间、浇注方法、铸型材料等。所以,在冒口尺寸计算过程中,偏大干安全系数,故铸钢件工艺出品率较低。通过我厂从一九八一年到一九八三年在不同结构铸件上,使用纤维复合型保温冒口套,实践证明,该冒口套材质是在保证铸件质 相似文献
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Wu ShipingWang RujiaChen WeiDai Guixin 《金属学报》2018,(2):247-264
The application of vibration technology to the metal solidification process can not only effectively improve the solidified structure and the performance of castings, but also have the advantages of low cost, energy saving and environmental protection. Therefore, the application of vibration technology in metal solidification has been extensively studied in experiments. However, due to the high temperature and opacity of the metal melt, hindering its measurement and observation, the mechanism how the vibration affects the solidification is not fully understood. Numerical simulation can provide the variation law of various parameters such as flow field, temperature field and stress field under vibration condition, which helps us understand the mechanism of vibration more thoroughly. Meanwhile, the numerical simulation of the influence of vibration on the solidification of metal melt has been much less systematically studied. This paper introduces the research progress of numerical simulation of vibration applied in metal solidification. The main vibration modes include ultrasonic vibration, mechanical vibration and pulsed electromagnetic vibration. The application mainly includes melt processing, filling, solidification, purification and ageing process of numerical simulation. The current research status of numerical simulation theory and technology of vibration applied in all aspects of casting was summarized systematically. Furthermore, the future research directions of numerical simulation of vibration in metal solidification process were prospected. 相似文献
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Solidification of Al alloys under electromagnetic field 总被引:5,自引:1,他引:5
崔建忠 《中国有色金属学会会刊》2003,13(3)
1 INTRODUCTIONCastingisakeystepinAlalloyprocessing .From productionweknowthatalmostallqualityproblemsarerelatedtothedefectsincasting ,mostofwhichcannotbeeliminatedinfollowingformingandheattreatments ,socastingisnotonlyaformingpro cessbutalsoaprocessforstructuralcontrol.Toapplyoutfieldisanefficientandeconomicalmethodtocon trolstructures .Theelectromagneticfieldiswidelyusedinindustry ,becauseofitshighefficiency ,econ omy ,cleannessandnocontact[15] ,forexample ,electromagneticstirring ,elec… 相似文献
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The heat transfer during the casting solidification process includes the heat radiation of the high temperature casting and the mold, the heat convection between the casting and the mold, and the heat conduction inside the casting and from the casting to the mold. In this paper, a formula of time step in simulation of solidification is derived, considering the heat radiation, convection and conduction based on the conservation of energy. The different heat transfer conditions between the conventional sand casting and the permanent mold casting are taken into account in this formula. The characteristics of heat transfer in the interior and surface of the casting are also considered. The numerical experiments show that this formula can avoid computational dispersion, and improve the computational efficiency by about 20% in the simulation of solidification process. 相似文献
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在精密铸造工艺设计中,一般是采用在热节圆的位置开设浇口、设置浇道或增加冒口来解决铸件缩孔、缩松等缺陷,使铸件在冷却、凝固过程中有效地形成补缩通道,获得优质的铸件,工艺设计的主要原则也来自于铸件的结构本身.运用热铁(贴)、冷铁的工艺方案,减少精铸件缩孔、缩松,通过从铸件外部冷却环境的改变来改善精铸件品质. 相似文献
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采用华铸CAE软件,对客车的球墨铸铁轮毂铸件的凝固过程进行了数值模拟,根据对铸造工艺方案的凝固模拟和实验结果分析,获得了1种合适的铸造工艺用于轮毂铸件生产,有效地消除了轮毂生产过程的缩孔、缩松缺陷。 相似文献
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本文考察了ZA27合金的壁厚效应及振动凝固对其的影响。结果表明,ZA27合金具有明显的壁厚效应,其主要原因是由铸件断面上的缩松所致。振动凝固可以减轻壁厚效应,获得具有较高机械性能的铸件。 相似文献