共查询到19条相似文献,搜索用时 375 毫秒
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开发了一种激光快速成型制备钼铜复合材料的新工艺,采用水悬浮包覆方法制备激光烧结成型用覆膜钼粉,对覆膜钼粉激光烧结成型工艺进行优化实验。对激光烧结成型件的后处理工艺,包括脱脂、高温烧结与熔渗进行了实验研究,制备钼铜复合材料样件。结果表明:激光烧结成型最佳工艺参数如下,激光功率15w,扫描速度1000mm/s,铺粉厚度0.1mm,预热温度60℃;钼铜复合材料的抗拉强度为383.8MPa,伸长率为6.6%,可以满足弹箭发动机喷管等高温零部件的实际使用要求。 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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介绍了用于薄壁铝合金铸件的真空差压铸造工艺。该工艺具有装置简单、充型速度平稳可调、充型能力好、铸件质量高的特点。对该工艺作了深入研究 ,论述了其基本原理。结果表明该工艺的压力时间曲线具有优良的线性关系 ,与传统的重力铸造和真空吸铸相比具有优异的充型性能 ,非常适用于薄壁铝合金铸件的生产 相似文献
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基于SLS塑料原型的金属零件的快速铸造 总被引:5,自引:1,他引:4
利用选择性激光烧结(SLS)快速成型工艺烧结塑料原型,结合精密铸造技术制出了金属零件。研究了原型用塑料粉受热裂解燃烧特点,并据此制订了从计算机三维模型到金属零件的快速铸造工艺。描述了陶瓷型壳的制备和金属零件的铸造工艺,并对零件的精度进行了测量。 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
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) 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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制备一种用于激光烧结成形的包覆不锈钢粉末。应用数值模拟预测结合实际测量方法,研究激光功率、激光束扫描速度、预热温度及铺粉密度等参数对激光烧结深度的影响。结果表明,随着预热温度、铺粉密度与激光功率增加,烧结深度增加;随着扫描速度增加,烧结深度降低。但当扫描速度不超过2 mm/s时,烧结深度随扫描速度的增加反而增大。提出一种利用数值模拟预测结果进行激光烧结工艺参数选择的方法。 相似文献