共查询到19条相似文献,搜索用时 187 毫秒
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Rapid manufacturing of metal components by laser forming 总被引:11,自引:0,他引:11
Edson Costa Santos Masanari Shiomi Kozo Osakada Tahar Laoui 《International Journal of Machine Tools and Manufacture》2006,46(12-13):1459-1468
This overview will focus on the direct fabrication of metal components by using laser-forming techniques in a layer-by-layer fashion. The main driving force of rapid prototyping (RP) or layer manufacturing techniques changed from fabrication of prototypes to rapid tooling (RT) and rapid manufacturing (RM). Nowadays, the direct fabrication of functional or structural end-use products made by layer manufacturing methods, i.e. RM, is the main trend. The present paper reports on the various research efforts deployed in the past decade or so towards the manufacture of metal components by different laser processing methods (e.g. selective laser sintering, selective laser melting and 3-D laser cladding) and different commercial machines (e.g. Sinterstation, EOSINT, TrumaForm, MCP, LUMEX 25, Lasform). The materials and applications suitable to RM of metal parts by these techniques are also discussed. 相似文献
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316L不锈钢激光快速成形的微观组织模拟 总被引:1,自引:0,他引:1
针对316L不锈钢激光快速成形(LRF)薄壁试样的凝固组织形态分布,从凝固理论出发,建立了激光快速成形柱状晶/等轴晶转变(CET)及一次枝距λ_1与有限元温度场耦合数值模型,模拟了成形高度为2.8 mm的LRF薄壁试样凝固组织形态及分布。结果表明:316L不锈钢LRF组织由致密、均匀、外延生长的细长柱状晶组成,一般不发生CET转变,组织中λ_1在6.5—17μm范围内,且随熔覆高度的增加而逐渐增大,模拟结果与实验符合很好。在此基础上,对成形高度为40 mm薄壁件的凝固组织形态及分布进行了预测。 相似文献
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P. Dunne S. P. Soe G. Byrne A. Venus A. R. Wheatley 《Journal of Materials Processing Technology》2004,150(3):201-207
Injection moulded components are finding vigorously increasing applications in numerous sectors. The flexibility of the process allows complex components to be manufactured in high volumes in fully automated environments. Associated with such components are equally complex tools whose manufacture is both expensive and time consuming. It is therefore vital that the component design be evaluated thoroughly with regard to both performance and manufacturability before commitment is made to expensive production tooling. The use of a physical prototype often provides the best method of design evaluation. The major routes to prototype manufacture are; material removal, rapid prototyping and rapid tooling. Rapid tooling techniques provide the most representative route, with the ability to produce polymeric prototypes (often in final material) by an injection moulding process.
Research has been undertaken into two rapid tooling processes; enhanced silicone moulding and sand moulding. Both processes involve casting material against a rapid prototype (master pattern) to form a mould which is then used in the manufacture of product prototypes by injection moulding. The focus of this paper is on the demands of these tooling techniques placed on rapid prototypes when used as master patterns. The demands are discussed in terms of surface finish, surface porosity, dimensional accuracy, thermal resistance and thermal expansion. 相似文献
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基于中空激光光内同轴送粉的激光快速成形工艺.对光粉耦合原理进行了分析。光内同轴送粉成形过程中,粉流稳定易控,光粉耦合性好。且金属粉末的有效利用率远高于传统光外送粉工艺。通过改变占空比和离焦量,得出两者分别对能量分布密度的影响.为工艺试验参数的选择提供依据。运用ANSYS有限元分析软件,对环形中空激光熔池三维流场和温度场进行了分析。环形中空光内熔池具有两对四环对流特点。随着熔覆层高度的增加。基板和熔池的温度会越来越高:激光束在基板和熔覆层表面经过的距离越长.温度场也发生明显变化.时间越长.温度越高。 相似文献
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Direct laser sintering of a copper-based alloy for creating three-dimensional metal parts 总被引:12,自引:0,他引:12
Y. Tang H.T. Loh Y.S. Wong J.Y.H. Fuh L. Lu X. Wang 《Journal of Materials Processing Technology》2003,140(1-3):368-372
Direct laser sintering of metal, as one of the important developments in rapid prototyping technologies, is discussed in this paper. A special copper-based alloy is used for this rapid prototyping process. Experiments on the sintering conditions of this material had been conducted in a self-developed high temperature metal sintering machine. The mechanism of laser sintering for this kind of material was disclosed by SEM analysis of microstructures of sintered parts. The density, surface roughness and mechanical properties of the laser sintering parts due to variation of process parameters were measured and analysed. The effect of process parameters to the accuracy of sintered parts was also investigated. Thus, optimum parameters were obtained for direct laser sintering of three-dimensional metal parts. 相似文献
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基于金属粉末的激光快速成型技术新进展 总被引:21,自引:0,他引:21
金属粉末的激光快速成型技术是集计算机辅助设计、激光熔覆、快速成型于一体的先进制造技术,是传统加工成形方法的重要补充。本文系统介绍了金属粉末激光快速成型的原理、系统组成及最新研究进展,并对其发展前景进行了展望。 相似文献