立式离心铸造的铅锡合金铸造机结构改进设计

分析了中空结构低熔点合金制件在立式离心铸造成型过程中质点受力状态,据此指出离心成型过程出现的壁厚不均现象的原因及解决方案,并提出在旋转过程中融入摆动运动以改善壁厚不均现象的方法,分析了该方法的可行性及相关工艺参数优化,且设计一种改进型摆动离心成型设备。通过实验验证了该设备对离心成型过程中壁厚不均现象具有改善作用。     

立式离心铸造熔体充填量的研究与模拟

通过受力分析，建立了立式离心铸造钛合金熔体充填流动的数学模型，以及相应的数值模拟模型；通过水力学试验模拟进行验证，与试验结果的良好符合，证明了数学模型的正确性及数值模拟结果的准确性。理论分析和试验结果表明，充填量随充填时间和离心转速的增加而增加，但是过高的转速却会导致型腔中熔体充填量的下降。     

地下水管接头立式离心铸造工艺

介绍了管接头铸件立式离心铸造工艺,其中包括设计原则和工艺参数.该工艺和重力铸造相比,提高铸件工艺出品率15%～30%,极大地改善了材料性能,降低了生产成本,获得了无缺陷高质量的铸件.     

汽缸套立式离心铸造机试验研究

研制了专用立式离心铸造机及其辅助工艺装备，谋求解决传统卧式离心铸造工艺在汽缸套生产中存在的问题。在现场生产条件下进行了试验研究，并与卧式离心机进行了对比     

立式离心场下钛合金熔体充填及凝固过程研究

研究立式离心场下不同铸造工艺参数对钛合金熔体的充填及凝固缺陷形成的影响。结果显示,立式离心场下得到的钛合金铸件质量优于重力场下的铸件。立式离心场下,合金熔体由于受离心力和科氏力的作用,沿着与旋转方向相对的型壁进行充填,且熔体的截面面积随充填长度的增加而逐渐减小,但是在内浇口处由于速度降低导致截面面积有所回升。此外,铸型的旋转方向,旋转半径及旋转速度直接影响铸件缺陷的形成。旋转方向直接影响合金熔体的充填顺序,进而影响合金熔体的凝固顺序及缺陷位置。实验结果显示,旋转半径及旋转速度的增加有利于减少铸件的缺陷体积。     

立式离心铸造合金铸铁复合轧辊

前言我厂铸造车间是生产中小型铸铁轧辊的专业车间.从1951年开始生产铸铁轧辊,是国内生产冶金工业使用的铸铁轧辊的最早厂家之一。目前年产量为17000～18000t,居全国中小型轧辊生产厂的第一位。近几年来由于高速线材轧机、无缝钢管张力减径机,塑钢和合金棒材轧机的引进。为之配套的优质轧辊对其性能和白口层的深度等提出了更高的要求。而     

地下水管接头立式离心铸造工艺

叙述了管接头铸件立式离心铸造的工艺,其中包括设计原则和工艺参数.它和重力铸造相比,提高铸钢件工艺出品率15%-30%,极大地改善材料性能和降低生产成本,能获得无缺陷高质量的铸件.     

离心铸造充型及凝固过程数值模拟

采用数值模拟技术优化进而控制生产,使离心铸造科学化生产是离心铸造技术提高的关键.本文借助流体流动方程及传热方程建立并开发了离心铸造数值模拟模型及软件,为科学指导离心铸造生产提供了科学保障和有效手段.     

复杂钛合金铸件立式离心铸造过程的数值模拟

利用三维可视化离心铸造数值模拟技术模拟某钛合金薄壁件的充型凝固过程,预测缺陷可能的位置。重点分析缺陷区域在不同转速下的缩松、缩孔分布情况,给出最佳转速。结果表明,缩松缩孔出现在铸件热节部位,与实际铸件X光检测显示一致。对比发现,在150r/min时的铸件缩孔明显减小。这是由于转速增大离心力增大,熔体充填型腔的能力增强,有效减小了缩孔体积,改善了缺陷情况。     

立式离心铸造机试生产事故原因分析及安全对策

针对一起立式离心铸造机在试生产过程中铸型顶盖脱落事故，根据流体静力学原理对金属液体进行受力分析，对模具顶盖螺栓材料进行强度校核，发现事故的直接原因是顶盖螺栓强度不足，建议从设计上加强设备的本质安全，制订并严格执行安全操作规程，定期对机器设备、铸型及其紧固装置等进行检查、维护和检修。     

Solidified structure of thin-walled titanium parts by vertical centrifugal casting

The solidified structure of the thin-walled and complicated Ti-6Al-4V castings produced by the vertical centrifugal casting process was studied in the present work. The results show that the wall thickness of the section is featured with homogeneously distributed fine equiaxial grains, compared with the microstructure of the thick-walled section. The grain size of the castings has a tendency to decrease gradually with the increasing of the centrifugal radius. The inter-lamellar space in thick-walled casting parts is bigger than that of the thin-walled parts, and the profile of inter-lamellar space is not susceptible to the centrifugal radius.     

Numerical simulation and experimental investigation of two filling methods in vertical centrifugal casting

1 Introduction Titanium alloys possesses a high potential for production of work pieces with high strength, mechani- cal properties and high corrosion resistance, which makes them widely applied in aviation, astronavigation and civil fields[1- 5]. However…     

Analysis of filling process of Ti6Al4V alloy melt poured in permanent mold during centrifugal casting process

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离心铸造Al-Fe合金凝固过程中的固相迁移运动

离心铸造Ａｌ－Ｆｅ合金凝固过程中的先析出相与合金液之间具有较大的密度差,在离心力场作用下,先析出相将沿径向由内向外迁移,致使初生相沿铸件向呈梯分布,根据离心铸造Ａｌ－Ｆｅ合金过程中固相迁移运动的特点,建立了描述这一运动过程的数学模型,并提出采用求平均速度的方法对固相迁移速度进行数值求解,求出了凝固过程中时刻固相迁移运动速度的分布情况,揭示了离心铸造Ａｌ－Ｆｅ合金过程中的固相迁移运动规律 。     

一种钛合金镜筒的石墨型离心铸造工艺

介绍了某光学设备上使用的钛合金镜筒铸件的石墨型离心铸造工艺.分析了铸件出现浇不足缺陷的原因,通过浇注系统的改进解决了铸件的成形问题,并最终获得了合格的钛合金镜筒铸件.     

Numerical model of solidification process in binary Al-Fe alloy under centrifugal casting

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｏｌｉｄｉｆｉｃａｔｉｏｎｐｒｏｃｅｓｓｏｆｂｉｎａｒｙＡｌ Ｆｅａｌｌｏｙｕｎｄｅｒｃｅｎｔｒｉｆｕｇａｌｃａｓｔｉｎｇｉｓｃｏｎｔｒｏｌｌｅｄｂｙｔｈｅｍａｓｓ,ｍｏｍｅｎｔｕｍ ,ｈｅａｔａｎｄｃｈｅｍｉｃａｌｓｐｅｃｉｅｓｔｒａｎｓｐｏｒｔａ ｔｉｏｎ .Ｔｈｅｒｅｆｏｒｅ,ｉｔｉｓａｎｉｍｐｏｒｔａｎｔｍｅａｎｓｔｏｋｎｏｗｔｈｅｍｉｃｒｏｓｔｒｕｃｔｕｒｅａｎｄｔｈｅｓｅｇｒｅｇａｔｉｏｎｏｆｂｉｎａｒｙＡｌ Ｆｅａｌｌｏｙｕｎｄｅｒｃｅｎｔｒｉｆｕｇａｌｃ…     

Control of equiaxed grains in a complicated Cu-Ni based alloy prepared by centrifugal casting

A complicated Cu-Ni based alloy was developed to fabricate wear-resisting bush for high temperature application.The concern focuses on the control of equiaxed grains in the developed alloy ingot prepared by centrifugal casting.The results show that the equiaxed grains are determined by the pouring temperature of the melt,the cooling rate and the rotation speed of the mold.With the decrease in pouring temperature,the fraction of the equiaxed grains in the transverse section of the ingot increases and the average length of columnar grain decreases.When the pouring temperature is confined below 1,250℃,complete equiaxed grains can be obtained.Based on the optimal centrifugal casting processing,the tensile strength of the developed alloy ingot with complete equiaxed grains reaches to 810 MPa and 435 MPa at room temperature and 500℃,respectively,which is 14% and 110% higher than that of common commercial QAl10-4-4 alloy.The wear rate of the developed alloy is 7.0 × 10-8 and 3.8 × 10-7 mm3?N-1?mm-1 at room temperature and 500℃,respectively,which is 5 times and 39 times lower than that of QAl10-4-4 alloy.     

离心铸造下微尺度充型流动的相似物理模拟(英文)

利用获得的相似准则,采用相似物理模拟方法,研究离心铸造过程中液态金属在微尺度空间内的充型流动规律。结果表明:在微尺度条件下,模拟流体优先充填横截面积最大的流道,当转速提高到964 r/min时,才会同时充填0.1 mm的微流道;在充型流动过程中,流体总能量保持不变,流体的自由液面是以转轴为圆心的规则圆弧面;充型速度随时间的增加而增大,迅速达到一个极值,然后随着时间的增加,变化逐渐趋于平缓,同时随着转速的增加充型速度达到峰值的时间也会极剧缩短。     

Wear properties and effect of molds on microstructure of graphite reinforced copper alloy composites made by centrifugal casting

Graphite reinforced copper alloy composites were cast using gravity and centrifugal casting techniques to identify the effect of graphite particles on microstructural formation and the effect of the casting techniques on the distribution of the particles. Melt containing either 5 or 120 μm size graphite particles were gravity cast in both steel and graphite molds. Melts containing 5 μm graphite particles were also cast in a horizontal centrifugal casting machine. Samples cast in the graphite molds exhibited much greater pore size than that found in the samples cast in the steel molds. Graphite particles moved to the inner periphery when influenced by centrifugal force, resulting in the formation of graphite-rich and graphite-free zones. The volume fraction of graphite particles near the inner periphery was 13%, which is higher than the initial volume fraction of graphite particles (7 vol.%) added into the melt. The results of wear testing showed that the friction coefficient of the pin from the graphite-rich zone is 0.49 and 0.69 for the pin from the graphite-free zone. The size of the machining chips from the graphite-rich zone was much smaller than those from the graphite-free zone. These results suggest that this composite may be an attractive substitute for copper alloys containing lead.     

铸造合金CoCrMoW锻造工艺的研究

通过对CoCrMoW合金电渣锭在两种不同的保温制度下保温后进行两种不同的锻造变形方式开坯锻造,研究了CoCrMoW电渣锭锻造保温温度及锻造变形方式对可锻性的影响。试验研究结果表明:CoCrMoW合金电渣锭在1220℃保温1 h后采用整体锻造,锻件的表面质量与内部质量良好;1200℃保温2 h后,采用整体锻造,锻件的表面质量良好,但是内部有缺陷产生;CoCrMoW合金电渣锭在1220℃保温1 h后锻造变形,电渣锭采用分段锻造时表面出现开裂,采用整体锻造时表面质量与内部质量良好;经过开坯后的小规格坯料再继续开坯或锻成品时,分段锻造与整体锻造均可采用。该合金合理的锻造保温温度为1220~1240℃,电渣锭锻造变形方式必须采用整体锻造;小规格锻造方坯变形方式宜采用整体锻造,但也可采用分段锻造。