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近年来,真空压铸技术在国内外得到了广泛的应用,目前国外高真空压铸的方法主要有3种,分别是来自德国的Vacural法和MFT(MinimumFillTime),以及来自日本的vaccumGolveBox法,国内学者也研制出了各种真空压铸方法。在真空压铸技术领域中,重点要解决是模具密封与真空截止阀的问题,本文总结了目前实际应用中的各种真空压铸方法与工艺,探讨了真空压铸技术在实际运用过程中面临的主要问题,并在此基础上开发设计了具有自主知识产权的锌合金高真空压铸造工艺法。 相似文献
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真空压铸的型腔气体排气理论分析 总被引:2,自引:1,他引:1
真空压铸能有效减少铸件内的气孔缺陷,提高铸件的致密度。将型腔内的气体快速排出是真空压铸技术的关键,也直接影响真空压铸件的质量。通过分析气体在真空排气管路中的流动物理过程,研究影响型腔真空度的主要工艺因素,提出使型腔快速达到高真空度的最优化工艺参数方案。结果表明,大截面、短距离的排气通道、大抽气速度,小抽气容积有利于型腔快速达到高真空度。 相似文献
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对不同慢压射速度条件下真空辅助对AZ91D镁合金压铸件组织及力学性能的影响进行了评估。在联合有自行改进的TOYO真空系统的TOYO BD-350V5型冷室压铸机上制备片状AZ91D镁合金压铸件。研究发现,充型时型腔真空压力随着慢压射速度的升高呈现3次方增长,导致真空辅助对压铸件中气孔的降低能力随着慢压射速度的降低而下降。常规和真空压铸件中压室预结晶组织(ESC)含量随着慢压射速度的变化趋势相似。在较低慢压射速度时,真空压铸件拉伸性能受ESC含量的影响很大,随着慢压射速度的升高,真空压铸件中气孔含量的影响将变得显著。 相似文献
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Laihua WangGary Savage 《Journal of Materials Processing Technology》2011,211(9):1510-1515
This paper presents the results of a quantitative study of the gas level in various types of castings from the high pressure die casting (HPDC) process using a vacuum fusion method. It was found that the major part of the gas was from the air entrapment during cavity filling. Other sources such as air entrapment during ladling, residual die lubricant and quenching water were also noticeable. Measurements of a large casting and castings from a multi-cavity die showed that the gas content was unevenly distributed. The modified vacuum fusion method has been proved to be a valuable tool for evaluating and quantifying the level of gas in castings as well as for an assessment of the influence of different process parameters on gas evolution in castings. 相似文献
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Volker R. Knobloch 《材料热处理学报》2004,(5)
1.Aluminum Casting Production Now andThenIt is well known that the reduction of the total weightof an automobile leads to a reduction in fuelconsumption(about0.5liters of100kilometers).Thisimproved fuel economy also reduces the CO2emissionsreleased into the atmosphere.As the size of vehicleshas grown,the overall weight has had to be decreased.The automotive industry is therefore using more andlighter metal components in order to reduce fuelconsumption and lower emissions.Production of cylin… 相似文献
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VolkerR.Knobloch 《材料热处理学报》2004,25(5):552-554
The interior of a high-pressure die-casting is of an unsatisfactory quality. Engine blocks made with this die casting process show lower specific engine performance. Pressure die-casting can hardly be heat treated for obvious reasons PSM (Precision Sand Molds) process uses sand and organic binder to generate a mold and even allows the manufacturing of complex diesel engine blocks in aluminum alloys. Combined technologies are available for semi-permanent mold castings with cores and castings made in Precision Sand Molds with organic binders. Castings are placed into the special heat treatment furnace immediately after pouting without the operations in stand alone machinery. This patented Sand Lion^R 3-in-1 technology processes hot castings and carries out three (3) foundry processes simultaneously in one (1) automated machine: 1) De-coring and sand removal; 2) Thermal sand reclamation; 3) Solution heat treatment of castings. The combination of several main casting processes is reflected in significant reductions of energy consumption, of production costs, and improving the quality of the castings. Audits in foundries using the 3-in-1 process showed an average reduction in production costs of more than 30%. 相似文献
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带内斜滑块脱螺纹机构的压铸模 总被引:1,自引:1,他引:1
铸件螺纹脱模是压铸模设计的难点之一。本文铸件内部有三等分的部分内螺纹,设计了内斜滑块脱螺纹机构。内斜滑块在推杆作用下推出铸件的同时,沿动模型芯导滑槽向内移动并脱出螺纹。论述了模具工作原理,并且通过胀型力的计算选择了压铸机,给出了工艺参数。模具工作可靠,生产效率高,成形工件满足质量要求。 相似文献
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周健波 《特种铸造及有色合金》2011,31(12):1125-1126
铸件带有完整的外螺纹,脱外螺纹机构的设计是该压铸模设计的难点.为此给出了齿条-锥齿轮脱外螺纹机构.通过齿轮啮合传动,带动螺纹型芯旋转,铸件在浇口余料的限制下静止不转,故脱离螺纹型芯.论述了铸件的工艺性,给出了模具的工作原理和工作过程. 相似文献
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针对铝合金铸件在压铸充填过程中常伴有气孔、缩孔、冷隔等缺陷的现象,以汽车铝合金变速箱外壳为例,分析变速箱外壳的结构特征,对其浇注系统、冷却系统、抽芯结构进行设计,确定最佳工艺参数,经过试验与分析,最终经过实际压铸生产验证,确定了工艺方案的合理性。结果表明:当定模温度为200℃、动模为220℃、铝液浇注温度为670℃、慢压射速度为0.18 m/s、快压射速度为4.5 m/s、内浇道的压射速度为48 m/s、留模时间为30 s时,铸件成形品质较好。合理压铸工艺设计不仅能提高生产效率以及产品的合格率,还能简化模具设计制造流程,减少模具开发成本。 相似文献
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针对广汽自主品牌"传祺"轿车的底盘铝合金后副车架压铸零件,从压铸合金的力学性能、压铸工艺设计及优化、模具设计及制造、铸件质量控制等方面进行了开发和研究。结果表明,采用耐热密封结构的高真空压铸模具具有良好的密封性能,可靠性高。多区域的温度测量及冷却水流量的实时调节提高了模具温度控制的精度。通过对工艺参数的优化,有效消除了铸件缺陷如裂纹、冷隔、缩孔、缩松等。开发的铝合金后副车架的铸件本体抗拉强度≥240MPa,屈服强度≥145MPa,伸长率≥6%,满足了"传祺"轿车的的使用要求。 相似文献
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以A380压铸铝合金为研究对象,设计了压铸工艺参数,通过密度测定、力学性能测试和金相观察,分析了压铸工艺参数对铸件性能的影响.研究表明,压力增加,铸件的密度和强度增加;压力一定时,压铸速度对铸件的力学性能有较大影响.使用改进的工艺,铸件抗拉强度达到365 MPa.伸长率达4.2%. 相似文献
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对比研究了液态压铸和半固态流变压铸对ZL114A铝合金铸件疲劳性能的影响。结果表明,半固态流变压铸件相较于传统液态压铸件疲劳性能更好而且更稳定。液态压铸件的疲劳寿命主要受孔洞尺寸影响,孔洞尺寸越大,疲劳寿命越低。半固态压铸件的疲劳寿命主要受密度(孔隙率)影响,与密度成正比。半固态压铸ZL114A铝合金试样在密度大于2.62g/cm^3时,疲劳性能表现良好。在70MPa应力下,疲劳寿命可达107次。液态压铸件裂纹萌生于大的气缩孔,半固态压铸件的裂纹萌生是于中心缩松多孔的综合作用结果。 相似文献
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在压铸生产过程中,铸件成型受到充填时间的限制,所以必须使用高速高压充型。在合金液凝固之前将其充满型腔才能保证铸件成型。在充型过程中,模具型腔内有部分气体来不及排放,以致使铸件内部形成气孔。本文介绍了感应式高真空压铸模具设计的要点,它是有效提高铸件质量的方法之一,供大家参考。 相似文献
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The effects of vacuum assistance on the microstructure and mechanical properties of high pressure die cast A390 alloy at different slow shot speeds were evaluated. Plate-shaped specimens of hypereutectic A390 aluminum alloy were produced on a TOYO BD-350V5 cold chamber die casting machine incorporated with a self-improved TOYO vacuum system. According to the results, the vacuum pressure inside the die cavity increased linearly with the increasing slow shot speed at the beginning of mold filling. Meanwhile, tensile properties of vacuum die castings were deteriorated by the porosity content. In addition, the average primary silicon size decreased from 23 to 14 µm when the slow shot speed increased from 0.05 to 0.2 m/s, which has a binary functional relationship with the slow shot speed. After heat treatment, microstructural morphologies revealed that needle-shaped and thin-flaked eutectic silicon particles became rounded while Al2Cu dissolved into α(Al) matrix. Furthermore, the fractography revealed that the fracture mechanism has evolved from brittle transgranular fracture to a fracture mode with many dimples after heat treatment. 相似文献