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21.
TiCp/Al预制块在Mg中熔化过程研究 总被引:4,自引:0,他引:4
将TiCp/Al预制块以不同的工艺加入到Mg液中进行熔化试验。结果表明,未搅拌时TiCp/Al预制块在800℃的Mg液中保温60min后仍不熔化,采用合适的搅拌工艺可使TiCp/Al预制块熔化,并且使TiC粒子在熔体中均匀分布。TiCp/Al预制块在Mg液中的熔化过程机理为:基体Al通过熔化和对淹扩散进入到Mg液中,TiC粒子间的结合力需通过搅拌产生的剪切力才能破坏,并随Mg液流动进入到Mg液中,机械搅拌可使TiC粒子Mg液中均匀分布。 相似文献
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M. Shiomi D. Takano K. Osakada M. Otsu 《International Journal of Machine Tools and Manufacture》2003,43(3):1737
In order to improve the mechanical properties of products, a forming process of a solid material at a temperature just below the melting point is proposed. The material is deformed at the semi-solid temperature due to the heat generation caused by plastic deformation. The tensile strength, elongation, hardness and toughness of the aluminium alloy (Al–7%Si–0.3%Mg) billet extruded at temperatures between 500 and 550 °C are compared with those of the billet extruded in the hot forming (450 °C) and the semi-solid (560 °C) temperatures. The billet temperature during forming is evaluated by the finite element simulation. The tensile strength and hardness of the billet extruded at 550 °C just below the solidus temperature are higher than those for a billet at 450 °C, and they are almost the same as those for a billet deformed at 560 °C in the semi-solid region. The elongation and toughness of the extruded billet at 550 °C are lower than those for a billet at 450 °C. The forming load at 550 °C is almost half of that at 450 °C. Cracking on the surface of the extruded billet occurs at a high punch speed. The calculated temperature when the solid billet is extruded in the semi-solid state agrees well with the experimental one at which the tensile and hardness are improved. 相似文献
25.
介绍了国内外冲天炉熔炼控制技术的发展状况。在分析国内铸造业具体情况后,提出了采用人工智能控制技术中的模糊控制理论对冲天炉熔炼控制的可行性和发展方向。 相似文献
26.
总结了双联熔炼工艺中灰铸铁熔炼材料的要求和特点,并针对使用过程中容易出现的问题进行了分析,同时分析了熔炼材料对铸件性能可能造成的影响,为合理选用熔炼材料提供了依据。 相似文献
27.
护环作为发电机一个最关键的零件,由于其所起的作用及受力状态决定了要求超高的强度、良好的塑韧性、无磁性及优秀的抗应力腐蚀的能力,为了提高制造18Mn-18Cr-n护环的强度等级,经分析认为提高护环钢中的氮含量是一个关键的因素,在对影响18Mn-18Cr-N钢中氮含量的因素进行分析研究及实验室小感应炉的模拟实验的基础上,编制出冶炼工艺,并在电炉上进行了6炉次的实践,钢中的氮含量达到了0.69%,氮的收得率最高达到71%,大大高于常规工艺方法的水平,达到了日本制钢所室兰工厂该钢种的氮含量水平。 相似文献
28.
介绍了Al-Li合金熔制用的一种新型涂料,作料具有化学稳定笥,不与Al-Li合金液反应,不腐蚀铁坩锅及工具,涂层均匀致密,易于喷涂的清理等特点,能有效地控制合金成分及杂质含量。 相似文献
29.
Laser beam weld-metal microstructure in a yttrium modified directionally solidified Ni3Al-base alloy
The microstructure of laser beam weld-metal of an yttrium doped directionally solidified alloy IC 6A, with chemical composition Ni–16Al–8.5Mo–0.12B–0.05C–0.03Y (at.%) was studied. The dendritic microsegregation observed within the fusion zone indicated that dendrite cores were slightly depleted in molybdenum and aluminum and the interdendritic regions were also considerably enriched in yttrium. Severe cracking in the weld-metal was observed and was found to be closely associated with interdendritic eutectic-type microconstituents identified as consisting of γ, γ′ and Ni–Mo phases. An yttrium-rich phase (Ni3Y) was observed in some interdendritic regions containing the eutectic γ, γ′ and Ni–Mo products. Their formation was discussed in relation to plausible microsegregation induced alteration of primary solidification path during cooling from welding temperatures. 相似文献
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Wjatscheslaw Missal Jaroslaw KitaEberhard Wappler Frieder GoraAnnette Kipka Thomas BartnitzekFranz Bechtold Dirk SchabbelBeate Pawlowski Ralf Moos 《Sensors and actuators. A, Physical》2011,172(1):21-26
A miniaturized ceramic differential scanning calorimeter (MC-DSC) with integrated oven and crucible is presented. Despite its small size of only 11 mm × 39 mm × 1.5 mm, all functions of a conventional DSC apparatus are integrated in this novel device - including the oven. The MC-DSC is fully manufactured in thick-film and green glass ceramic tape-based low temperature co-fired ceramics (LTCC) technology. Therefore, production costs are considered to be low. Initial results using indium as a sample material show a good dynamic performance of the MC-DSC. Full width at half maximum of the melting peak is 2.4 °C (sample mass approx. 11 mg, heating rate approx. 50 °C/min). Repeatability of the indium melting point is within ±0.02 °C. The melting peak area increases linearly with the sample mass up to at least 26 mg. Simulations of a strongly simplified finite element model of the MC-DSC are in a good agreement with measurement results allowing a model-based prediction of its basic characteristics. 相似文献