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针对汽车镁合金转向器铸件,采用数值模拟的方法研究了其真空压铸成形过程,分析了在高真空度条件下金属液充型的特点,并在此基础上对比研究了在高真空度、低真空度以及常压条件下充型及凝固的规律。结果表明,提高型腔真空度能有效地提高金属液充型能力,避免铸件内气孔的产生,但对缩孔、缩松缺陷的形成没有影响。 相似文献
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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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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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Development of vacuum die-casting process 总被引:1,自引:0,他引:1
Masashi Uchida 《中国铸造》2009,6(2):137-144
The vacuum die-casting process, started 25 years ago in Japan, has been widely applied. This technology contributes very much to improvement of castings quality. The main factor causing the defects of die castings is the trapped air in the mold cavity, while the key technology of vacuum die-casting process is to avoid the trapped air effectively by evacuating the cavity before casting. At the same time, due to the shot speed and the casting pressure reduced in half, the service life of the die is prolonged and the productivity is enhanced, as well. Vacuum die-casting process is of great significance in improving the die castings quality and making up the shortcomings of super-high-speed shot casting. 相似文献
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The feasibility of semi-solid die casting of ADC12 aluminum alloy was studied. The effects of plunger speed, gate thickness, and solid fraction of the slurry on the defects were determined. The defects investigated are gas and shrinkage porosity. In the experiments, semi-solid slurry was prepared by the gas-induced semi-solid (GISS) technique. Then, the slurry was transferred to the shot sleeve and injected into the die. The die and shot sleeve temperatures were kept at 180 °C and 250 °C, respectively. The results show that the samples produced by the GISS die casting give little porosity, no blister and uniform microstructure. From all the results, it can be concluded that the GISS process is feasible to apply in the ADC12 aluminum die casting process. In addition, the GISS process can give improved properties such as decreased porosity and increased microstructure uniformity. 相似文献
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分析了压铸件气孔、缩松、夹杂、冷隔、尺寸超差及表面质量问题等缺陷特征,从模具设计、熔炼工艺及涂料使用等方面对缺陷产生的原因进行了探讨。结果发现,在合理的零件结构基础上,通过改进浇注系统,调整模具温度及金属液温度,并采用正确的喷涂方法,可有效防止压铸件缺陷的产生。 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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基于快速原型的转移涂料法制作模具技术 总被引:11,自引:0,他引:11
将快速原型制造与转移涂料精密铸造结合,对复杂曲面金属模具的快速制作方法进行了探索。该方法用三维造型软件设计模具,用分层制作技术快速得到模具原型,再基于原型直接采用转移涂料工艺,制作出近净型金属模具毛坯。该工艺流程短,成本较低,特别适合砂型铸造或消失模铸造用的小型金属模具的快速制作。 相似文献
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Alloys with an equiaxed microstructure exhibit significantly lower flow resistance in the semisolid state than alloys with
a dendritic microstructure. Their thixotropic behavior (solidlike in the unperturbed state and liquidlike during shearing)
has been the basis for a thixoforming process. It is accepted today that thixoforming is a new net-shaped manufacturing technology
in which the billet is heated to the semisolid state with coexisting solid-liquid phases.
The thixoforming process has some industrial advantages, such as the successful fabrication of high-quality components with
fewer inner defects, suitable for less machining, high productivity comparable to high-pressure die casting, and being an
energy-saving system without the conventional melting process. It consists of inductive coil design, a billet reheating process,
billet handling, filling into the die cavity, and solidification of the thixoformed part.
This work presents an overview of all the detailed stages in the thixoforming process to manufacture the net-shaped product
with good mechanical properties. An air compressor part with high strength has been fabricated by the thixoforming process. 相似文献
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针对压铸成形的ADC14汽车离合器齿轮厚壁部件,研究了适于压铸的过共晶Al-Si合金的P-Cu变质处理工艺。设计并模拟了齿轮的压铸工艺方案,开发了真空压铸及局部加压技术。结果表明,当P的加入量为0.1%时,ADC14的变质效果好,变质时间可达6h。铸件中初生Si尺寸为20~40μm,分布均匀;铸件表面的Si贫乏区深度在0.18~0.20mm范围内。在相同压射参数下,采用机械式真空阀比搓衣板式排气阀的真空效果好,铸件的气孔缺陷废品率下降10%以上。优化后的局部加压技术消除了厚壁部位的缩松缺陷,提高了铸件内部质量。批量生产合格率达95%以上。 相似文献
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S queeze casting has been widely used for automotive struc tural parts because it offers a vast material selection from aluminum and magnesium alloys. In comparison with low pressure die casting, squeeze casting also overcomes many fluidity problems and thus it can use both hypereutectic and hypoeutectic alloys such as 319, 383 and 390. Squeeze casting can also apply “spot solidification” technology in addition to directional solidification method. The shortcoming of directional solidificati… 相似文献
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This paper presents an infiltration casting technique for manufacturing big size open-cell aluminum foam boards. The principle and key technologies of infiltration casting are also analyzed. Based on the previous practice of the small size aluminum foam production, the die for preparing big size aluminum foam boards is designed and manufactured. The experiments on aluminum boards of 300 mm × 300 mm × (20-75) mm, with the pore size ranging from 1.0 to 3.2 mm and average porosity of 60%, have been performed. The experimental results show that a reliable infiltration process depends critically on the pouring temperature of the molten AI-alloy, the preheated temperature of the mould and salt particles and vacuum. Current research explores the possibility of large-scale manufacturing and application of the aluminum foams. 相似文献
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This paper provides an overview of alloy and process developments in aluminum and magnesium castings for lightweight automotive applications.Wear-resistant aluminum alloys,creep-resistant and high strength/ductility magnesium alloys have been developed for automotive applications.On the process front,vacuum-assisted die casting and high vacuum die casting technologies have been developed for high-integrity body and chassis applications.Thin-wall and hollow casting components are being produced by low-pressure die casting processes for structural applications.Overcasting technology is gaining traction and has enabled mixed material designs for automotive sub-systems such as engine cradles and instrument panel beams.Simulation tools developed to predict the interfacial interactions of the dissimilar components and the structural integrity of the overcast systems are being validated in the casting trials. 相似文献
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真空压铸的发展 总被引:2,自引:3,他引:2
陈金城 《特种铸造及有色合金》1996,(5):32-33
真空系统是压铸过程中排除气体的最有效的方法之一。然而,真空压铸的发展几经起伏,现在则发展到一个新的阶段。从模具中抽出气体是几种抽气方法中较为简便的一种。真空气道的设计与常规气道则有所不同 相似文献
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针对压气机壳铝合金重力浇注铸件,依据孔洞缺陷的具体形态,对铸件表面或内部常出现的孔洞类缺陷进行了观察、分析、归类,并对其形成机理进行了分析。结合缺陷的产生机理和生产过程实际情况,从工艺和生产管理角度提出了孔洞缺陷的预防控制措施。结果表明,减少孔洞类缺陷的产生,从而保证铸件质量,节约生产成本。 相似文献