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本文对冷床上卸钢液压系统存在的问题进行了分析,找出了产生问题的原因,并对原液压系统进行了改造,减少了油液的泄漏,提高了系统的稳定性,减小了维修强度,降低了维修成本,提高了系统的工作效率。 相似文献
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分析了电脑机箱挡板的结构特点,设计了少废料排样,提高了材料利用率。应用了独特的切舌定距方案,满足了制件尺寸精度要求,简化了定位装置结构。模具结构设计简单、合理、可行,降低了模具成本、缩短了模具制造周期。 相似文献
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分析了计数器齿轮的冷模锻工艺,设计了冷模锻件图,计算及选用了毛坯尺寸及形状,验算了许可变形程度,选择了变形用的设备,拟制了冷模锻前的毛坯处理及设计了冷模锻模具结构。 相似文献
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分析了保压阀支架的冲压工艺,设计了零件的排样方案,介绍了模具结构。不仅保证了零件的精度,同时提高了生产率,大幅降低了生产成本。 相似文献
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本文通过生产实践,提出了拖拉机变速箱体产生裂纹的原因是内应力超过了抗拉强度所致。采用型内孕育,改善了铸件的组织结构,提高了抗拉强度,抵消了冷却不均匀所产生的内应力,消除了裂纹,提高了经济效益。 相似文献
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分析了望远镜镜身的结构,提出了塑件成型及模具设计的关键点,设计了模具的整体结构。设计了可相对运动的组合式型芯,以增加内抽芯机构的运动空间,通过塑件推出时带动螺纹滑块的移动实现了内侧抽芯。设计了矩形型芯镶块、加工了避空结构,采用螺钉固定,解决了狭小空间安装小型芯的问题,避免了模具干涉。采用了锥面配合,提高了模具的定位精度,减小了配合件的摩擦。经生产验证,该模具生产的塑件质量满足图纸要求。 相似文献
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When a metallic element is alloyed with each of the rare-earth elements, a systematic variation in the physical properties is observed. Examination of the variations as a function of rare-earth atomic number is a useful tool in evaluating rare-earth binary phase diagrams. 相似文献
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CRYSTAL DEFECTS IN PLASMA NITRIDED LAYER CATALYZED BY RARE EARTH 总被引:1,自引:0,他引:1
F.S.Chen Y.X. Liu D.K. Liang L.M. Xiao School of Materials Science Technology Shandong University Jinan China 《金属学报(英文版)》2002,15(2):243-247
1. IntroductionPlasl1la l1itridillg catal}'zed b}' rare-earth (RE) ele1llel1ts has beel1 a s1lccessf1[ltecllllolog)-["'], however it also causes a llul11ber of problenls. FOr exan1ple. tx-lly tlle REllas the catalytic effect or l1oxt' RE effects ol1 the s… 相似文献
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稀土对低碳钢热浸渗铝扩散系数的影响 总被引:1,自引:0,他引:1
研究了热浸渗铝液中添加微量稀土元素对低碳钢热浸渗铝时铝的扩散系数的影响,结果表明,稀土元素能增大铝原子的扩散激活能,降低铝原子的扩散系数。 相似文献
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稀土对Zn—5Al合金超塑性的影响 总被引:3,自引:2,他引:1
在Zn-5%Al合金中添加适量稀土元素,可形成Al2CeZn2,CeZn3等化合物,提高合金的超塑变形速率和伸长率,加入过量的稀土则对超塑性能有不利的影响。 相似文献
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Dr. H. Horie Mr. S. Hiratsuka Mr. T. Kowata Mr. Y. Iwamochi Mr. Y. Shobuzawa Mr. M. Nakamura 《International Journal of Cast Metals Research》2013,26(2):73-81
AbstractEight rare-earth elements, Y, La, Ce, Pr, Nd, Sm, Dy, and Yb, were added individually to two irons, one containing 0.02% S and the other 0.08% S. After nodularisation, the metal was poured into CO2 Process sand moulds to produce stepped test-specimens with thicknesses of 3,6 and 9 mm and into shell moulds to provide ‘break-off’ type specimens with a dia of 30 mm. The effect of each of these rare earth elements on the nodule number, and chill formation was investigated and the mechanism of the nodule number increase studied.The increase in the nodule number differed significantly with each kind of rare-earth element added to the molten iron. The largest rise in the nodule number was with Ce followed in turn by La, Pr, Nd, Sm, Yb and Y. It was seen that the increase in nodule number was more pronounced when the elements were added to the iron with the higher sulphur content. To maximise the increase in nodule number, it was found that the optimum added quantity of these rare-earth elements was almost stoichiometric with the sulphur content of the iron.X-ray microanalysis of the prepared specimens containing these rare-earth elements confirmed that only sulphides formed in the melts treated with Ce, La, Pr, Nd, or Yb, whilst both sulphides and phosphides formed when additions were made of Dy, Sm or Y. The specimens poured into a metal mould during the eutectic solidification stage, and subsequently quenched showed that graphite had formed on the rare-earth sulphide substrates, but not on the phosphide. It was concluded that the latter cannot act as substrates for the formation of graphite.Measurement of the average diameters of the rare-earth sulphides (Ce, La, Pr, and Nd) showed that the largest effects upon nodule numbers were associated with elements producing sulphides of smaller diameter. This phenomena may reasonably be explained. A rare-earth sulphide exists as a liquid phase in an iron melt and aggregates until it solidifies, increasing its diameter. The degree of aggregation differs amongst the different rare-earth sulphides, resulting in a different number of substrates for each graphite formation. 相似文献
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为研究混合稀土元素在金银铜合金内部的分布状态以及混合稀土元素的添加对金银铜合金硬度的影响,使用真空中频感应炉制备了Au-35Ag-5Cu、Au-35Ag-5Cu-1RE合金,并对铸态合金进行不同变形量的轧制加工,探讨了稀土元素的添加、变形量对合金组织及维氏硬度的影响。使用EDS进行了稀土元素分布检测、DSC分析固液相线温度并进行维氏硬度的测量等。结果表明,稀土元素La、Ce、Pr、Nd占据了Au、Ag元素的位置,改变了AuAg两种元素的分布,与Cu固溶效果较好,对Cu元素分布没有显著影响。稀土元素的添加降低了Au-35Ag-5Cu的液相线温度和固相线温度,增大了液相线温度和固相线的温度差。混合稀土元素的添加有助于提高铸态及轧制态金银铜合金的耐磨性。 相似文献
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A REVIEW ON THE BEHAVIOR OF THE ADDITION OF RARE-EARTH IN STEEL 总被引:2,自引:0,他引:2
一、稀土元素对钢性能的影响 二、稀土在钢中的基本作用 2.1 稀土的净化作用及对夹杂物形态的影响 (1) 稀土的脱氧作用 (2) 稀土金属的脱硫作用及对硫化物形态的控制作用 (3) 稀土的其他净化作用及对其他夹杂物形态的影响 2.2 稀土的合金化作用及其与间隙原子的交互怍用 三、稀土的加入方法 四、关于稀土钢浇注结瘤问题 相似文献