共查询到18条相似文献,搜索用时 187 毫秒
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半连续铸造法制备AlCu/Al梯度材料 总被引:10,自引:0,他引:10
提出了一种制备梯度材料的双流浇注连续铸造新方法 ,采用该方法在自制的半连续铸造装置上进行了AlCu/Al梯度合金的探索试验。分析了制备合金的组织和性能特点。结果说明 :采用半连续铸造方法在Al Cu系合金中可以实现合金成分随铸件横截面的连续梯度变化 ;合金的成分、显微组织和力学性能之间有较好的对应关系。 相似文献
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采用双流浇注半连续铸造方法制备了一种内层设计成分为镁合金、外层成分为纯铝的Mg-Al/Al梯度复合材料。试验表明,采用双流浇注连续铸造技术可以实现内层镁合金和外层纯铝之间的冶金结合,并且可在两层之间形成成分和硬度梯度分布的过渡层。所制备的合金材料在成分分布、宏观组织以及硬度分布之间有较好的对应关系。但由于两种合金的密度相差较大,容易导致内、外浇包熔体的剧烈混合,使得内层合金成分变化很大。 相似文献
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半连续铸造制备7075/6009铝合金梯度复合材料 总被引:3,自引:0,他引:3
采用双流浇注半连续铸造技术制备了7075/6009铝合金梯度复合材料.分析了合金内层、过渡层、外层的宏观和微观组织形态以及成分分布,并测量了铸件径向的洛氏硬度.结果表明,通过合理控制铸造参数,可以获得具有成分梯度和硬度梯度分布的7075/6009复合材料;梯度复合材料在凝固过程中.内、外合金熔体以紊流复合;过渡复合层的宽度主要受到内、外熔体的浇注温度、节流片孔径大小以及内导管插入结晶器深度的影响. 相似文献
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半连续铸造制备2024/3003梯度材料的研究 总被引:4,自引:5,他引:4
采用双流浇注半连续铸造方法制备了2024/3003铝合金梯度材料。研究了节流孔径和内浇包熔体温度两个工艺参数对铸件的成分分布,宏观组织和洛氏硬度的影响,结果表明,在保证铸造过程顺利进行的前提下,适当增大节流孔径和升高内浇包熔体温度都能增加铸件中内部合金的体积分数。合金的成分、宏观组织和力学性能之间的对应关系说明双流浇注半连续铸造方法制备2024/3003多元铝合金梯度材料是可行的。 相似文献
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从宏观的角度总结了影响双流浇注连续铸造制备铝合金梯度材料的因素,分析了确定浇注温度、铸造速度、内浇包的导流管设计等关键工艺参数时需要注意的问题,以便控制上述参数在一定的范围内变化,确保铝合金获得所期望的梯度分布。并以2024/3003合金的制备为例,提供了一些操作可行的参数,这些工作将为双流浇注连续铸造制备铝合金梯度材料提供指导。 相似文献
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采用双流浇注半连续铸造方法制备了直径为65mm的7075/6009铝合金梯度材料。研究了内导管节流孔径对铸件的成分分布、宏观组织和洛氏硬度的影响,重点分析了该工艺参数对研制合金界面组织特征的影响。结果表明,7075/6009复合材料铸锭中存在一个5mm左右的过渡层,过渡层与外层合金之间的界面清晰,但与内层合金的界面难以区分。在保证铸造过程顺利进行的前提下,适当增大节流孔径能显著减少铸件外层合金的厚度,但对过渡层厚度的影响很小。 相似文献
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内浇包熔体温度对7075/6009梯度合金组织性能的影响 总被引:1,自引:0,他引:1
采用双流浇注连续铸造方法制备了直径为65mm的7075/6009梯度复合铝合金铸件。分析了不同内浇包熔体温度对铸件横截面上的微观组织、成分分布和性能变化的影响。结果表明:内浇包熔体温度显著影响7075/6009合金的组织和性能,当内浇包熔体温度从680℃升高到730℃时,外层合金平均厚度减少约4.0%;当内熔体温度从730℃升高到780℃时,外层合金的平均厚度减少了25.0%。在内层合金和外层合金之间存在一个Zn、Cu含量和硬度连续降低的梯度过渡层,过渡层宽度随内层合金熔体温度的升高而增大,但增幅很小。 相似文献
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以“⊥”型和棒状试样为例,研究了反重力条件下,铸造工艺参数对ZL205A合金铸件充型性能和凝固组织的影响。结果表明,对于平均壁厚小于3 mm的薄壁铸件,由于差压铸造充型过程比低压铸造平稳,所以铸件成形更好,但无法成形尖角结构;提高浇注温度或铸型预热温度,均能使差压铸造薄壁ZL205A合金铸件的充型性能得到改善,且提高浇注温度效果更明显。与低压铸造相比,差压铸造可显著细化ZL205A合金晶粒度,适当提高浇注温度与铸型温度,均能进一步细化晶粒,且提高浇注温度使晶粒细化效果更显著。对于有一定截面厚度的ZL205A合金铸件,差压铸造时,当截面厚度超过一定量时,充型性能受铸型温度及浇注系统设计的影响较小,提高铸型温度,铸件产生孔洞类缺陷的几率显著增加。 相似文献
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《International Journal of Cast Metals Research》2013,26(4):254-258
AbstractThermal analysis technique relies on the cooling curve obtained when the sample is cooled in a sampling cup. This may not represent the cooling behaviour of the real casting. The microstructure developed during solidification depends not only on the nucleation and modification potential of the melt but also on the thermal gradient imposed during solidification by the mould. The factors affecting the thermal gradient are the mould material and casting section thickness. In the present investigation the effect of modification melt treatment, cooling rate and casting section thickness on the thermal analysis parameters of A357 alloy was studied. It is found that the dimensionless heat flux parameter is high for small section thickness castings. The metal/mould interfacial heat flux is high in a copper mould. Thermal analysis parameters of A357 alloy are found to be affected significantly by the combined action of modification, chilling and section thickness. 相似文献
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参照工业多流半连续铸造结构,设计了试验用单流半连续铸造铝合金设备,并使用该设备进行半连续铸造7075铝合金,为工业多流半连续铸造提供试验基础。对比研究了铸造速度、热顶结构等对铸锭表面质量的影响。研究发现:提高铸造速度仅仅能减弱冷隔,而无法消除冷隔;降低临界铸造速度虽然能得到光洁表面的铸锭,但无法进行稳定长时间半连续铸造,无法在工业上应用;减少overhang无法解决铸锭表面质量问题;热顶与结晶器之间的三角区被润滑剂填充后,能够实现稳定半连续铸造,并得到表面质量合格的铸锭。 相似文献
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《Journal of Materials Processing Technology》2014,214(9):1928-1934
An aluminum foam sandwiches (AFSs) consisting of ADC12 Al–Si–Cu die casting aluminum alloy foam and ADC6 Al–Mg die casting aluminum alloy face plates were fabricated. Using ADC12 die casting plates containing large amounts of gases as the starting material of the foam, ADC12 foam can be fabricated without using a blowing agent. Using FSW, both the uniform dispersion of the segregated gases and pore stabilization powder in the ADC12 die casting plates used to fabricate a foamable ADC12 precursor and the bonding of the ADC12 precursor to the ADC6 plates can be simultaneously achieved. Namely, the AFS precursor is expected to be obtained in fewer processing steps. From the visual observation of the fabricated AFSs, no deformation of the ADC6 plates occurred and the ADC6 plates on both sides of the aluminum foam remained parallel. From the X-ray CT observation of the fabricated AFSs, good pore structures without the infiltration of ADC12 foam into the ADC6 plates can be obtained at a holding temperature of 948 K and holding times of t = 10 and 11 min. In tensile tests on the fabricated AFSs, fracture occurred in the ADC12 foam parts but no fractures were observed at the bonding interface between the ADC12 foam and the ADC6 plates, that is, good bonding was obtained between the ADC12 foam and the ADC6 plates. 相似文献
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Lazar Kovačević Pal Terek Damir Kakaš Aleksandar Miletić 《Journal of Materials Processing Technology》2012,212(9):1856-1861
A thin wall Al–9 wt.% Si alloy casting was made in a sand mold prepared by CO2 process. The thermal history obtained from the experiment was used to solve an inverse heat conduction problem (IHCP). The IHTC was estimated by an iterative algorithm based on the function specification method. Acquired IHTC values are given as a function of time and as a function of the casting surface temperature at the interface. It has been found that pattern of IHTC variation with casting surface temperature can be described by an equation which has been proposed as a new correlation model. In order to verify broader applicability of the proposed correlation, its use is demonstrated on the IHTC results taken from the literature. 相似文献