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对某商用车前接梁样件采用ProCAST数值模拟技术辅助分析铸造工艺设计可靠性,确保样件制造的一次合格率;通过选择性激光烧结技术(SLS),以聚苯乙烯为原料打印模样,再进行熔模铸造工艺生产,最终获得符合尺寸和精度要求的样品。 相似文献
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基于覆膜砂激光快速成型的无模快速铸造方法研究 总被引:2,自引:0,他引:2
用激光扫描覆膜砂,当激光功率足够大时,覆膜砂的树脂膜会发生过烧和炭化而失去粘结作用。利用此特点,本文提出一种以激光扫描零件轮廓边界为基础的直接生成铸型的方法:用大功率激光逐层扫描出零件各层的轮廓边,相当于在覆膜砂上扫描出目标模型与砂型的分割面,对砂箱整体进行加热固化后,可得到三维的目标模型和砂型。本文给出了由此方法实现快速铸造的工艺方案,并进一步实现了金属零件的快速铸造。该方法有别于SLS工艺的面域扫描,具有分层简单、成型时间短、速度快、成型件强度高的特点,实现了铸造零件CAD/CAM的计算机集成制造,对缩短新产品开发周期和降低成本具有重要的意义。 相似文献
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《中国铸造》2004,(2)
1 .Introduction Based on the parameters and cross-section's information from a CAD model, the selected laser sintering (SLS) uses a laser beam to sinter selectively powdered solid materials (plastic, wax, ceramic, metal, etc.), and the solidified material is built up layer by layer to formthepart needed} As there are still some problems in material and technology, it is difficulty to sinter or produce directly 相似文献
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基于选择性激光烧结技术的快速铸造 总被引:8,自引:0,他引:8
介绍了用选择性激光烧结(SLS)快速成型技术直接制造覆膜砂铸型(芯)的特点及工艺过程。结合铸件生产,分析研究了SLS铸型(芯)的工艺设计、三维实体造型及铸型后处理等过程中所遇到的问题。 相似文献
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Turbine blades, produced by the directional solidification(DS) process, often require high dimensional accuracy and excellent mechanical properties. A critical step in their production is the fabrication of wax patterns. However, the traditional manufacturing process has many disadvantages, such as long-term production, low material utilization rate, and the high cost of producing a complex-shaped wax pattern. Selective laser sintering(SLS) is one of the most extensively used additive manufacturing techniques that substantially shortens the production cycle. In this study, SLS was adopted to fabricate the wax pattern instead of the traditional manufacturing process. The orthogonal experiment method was carried out to investigate the effects of laser power, scanning speed, scanning space, and layer thickness on the dimensional precision and morphologies of the SLS parts. The SLS parts showed a minimum dimensional deviation when laser power, scanning speed, scanning space, and layer thickness were 10 W, 3000 mm·s-1, 0.18 mm, and 0.25 mm, respectively. In addition, the tensile strength and fracture morphologies were closely associated with the laser volumetric energy density(VED). The tensile strength reached a maximum when the VED was 0.0762 J·mm-3, with an evident brittle fracture morphology. The wax pattern manufactured in this way meets the accuracy and strength requirements for investment casting. This research offers a novel path for the production of wax patterns for complex-shaped turbine blades by SLS. 相似文献
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As a precision casting process, investment casting process has been used widely in casting industry because of its many advantages. For almost all alloys, complicated near-net-shaped components can be cast relative easily and both external and internal designed complex castings can be achieved using investment casting. Investment casting is usually required for making complex shape castings while other manufacturing processes are too costly and time-consuming [1]. Conventional investment casti… 相似文献
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1 .IntroCtion Seleetive Laser Sintering(SLS)15 an imPortant field ofRaPid PrototyPing(RP),due to its caPability ofProeessinga very wide range ofmaterialsinadireetway.AtPresent,most of sintering materials are nonmetallie, 相似文献
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建立了基于SLS的石膏型快速精密铸造成形工艺流程.以某铝质发动机进气管的快速样件制造为例,确定了成形各个环节的工艺参数,得到了合格的零件.分析了影响石膏型快速精密铸件形状与尺寸误差、表面与内部缺陷的主要成因,探讨了提高铸件成形质量的工艺措施. 相似文献
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Titanium castings using laser-scanned data and selective laser-sintered zirconia molds 总被引:3,自引:0,他引:3
Nicole R. Harlan David L. Bourell Joseph J. Beaman Reuben Reyes 《Journal of Materials Engineering and Performance》2001,10(4):410-413
Titanium casting molds, made of stabilized and unstabilized zirconium oxide, were created using a combination of selective
laser sintering (SLS) and colloidal infiltration. The mold material system was chosen for its thermal shock resistance and
low reactivity with molten titanium. The starting material, stabilized zirconia powder mixed with a copolymer binder, was
laser sintered into the desired green shape. The binder was removed during pyrolysis and replaced by unstabilized zirconia.
As infiltrant weight gain increased, the density, flexural strength, and surface roughness improved to levels adequate for
titanium casting trials. A half-scale casting mold for the ball of a human femur bone was produced from laser-scanned data
and cast with Ti-6Al-4V alloy. The castings exhibited an as-cast surface roughness (R
a
) of 8 μm and a typical microstructure. This work demonstrates a feasible method of producing complex titanium castings for
one-of-a-kind and custom components without the necessity of part-specific tooling or wax patterns. 相似文献
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Within the project "Functional Surfaces via Micro-and Nanoscaled Structures" which is part of the Cluster of Excellence "Integrative Production Technology" established and financed by the German Research Foundation (DFG),an investment casting process to produce 3-dimensional functional surfaces down to a structural size of 1μm on near-net-shape-casting parts has been developed.The common way to realize functional microstructures on metallic surfaces is to use laser ablation,electro discharge machining or micro milling.The handicap of these processes is their limited productivity.The approach of this project to raise the efficiency is to use the investment casting process to replicate microstructured surfaces by moulding from a laser-microstructured grand master pattern.The main research objective deals with the investigation of the single process steps of the investment casting process with regard to the moulding accuracy.Actual results concerning making of the wax pattern,suitability of ceramic mould and core materials for casting of an AlSi7Mg0.3 alloy as well as the knock-out behavior of the shells are presented.By using of the example of an intake manifold of a gasoline race car engine,a technical shark skin surface has been realized to reduce the drag of the intake air.The intake manifold consists of an air-restrictor with a defined inner diameter which is microstructured with technical shark skin riblets.For this reason the inner diameter cannot be drilled after casting and demands a very high accuracy of the casting part.A technology for the fabrication and demoulding of accurate microstructured castings are shown.Shrinkage factors of different moulding steps of the macroscopic casting part as well as the microscopic riblet structure have been examined as well. 相似文献
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介绍了在广泛考察国内外制造随形冷却通道注射模技术的基础上,摈弃普遍采用的直接制模技术,提出将选择性激光烧结(SLS)技术和铸造工艺相结合,间接快速制造随形冷却通道注射模的新的制造工艺方法。利用SLS技术对腹膜砂和环氧树脂混加的材料成型注射模的布尔结构铸造砂型,对砂型进行后处理后,浇注铝合金形成模具铸件,最后对模具铸件进行清粉和后处理,完成注射模制造。同传统的随形水路模具制造技术相比较,本方法能成型较为复杂的随形冷却通道,并且由于直接用铝合金铸造成模具,其致密度、强度和尺寸精度相比较传统的脱脂、高温烧结和低温浸渍改性的环氧树脂等工艺方法得到的模具性能大幅度提高。该注射模寿命可达50 000次/副,强度可达588 MPa。从塑件质量可以得出,此工艺是一种快速制造适合小批量生产注射模的切实可行的方法。 相似文献