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研究了快速、精确制造金属模具的方法,提出利用激光选区烧结(SLS)技术来快速制造高精度陶瓷型精密铸造用母模.首先,采用正交试验法研究了激光选区烧结工艺参数对制件精度的影响,确定了最佳激光烧结工艺.在此基础上利用浸水起模法替代传统的起模喷烧工艺对陶瓷型精密铸造工艺进行改进.结果表明,选定激光烧结工艺参数为激光功率25 W,扫描速度2.0 m/s,扫描间距0.19 mm,分层厚度0.25 mm时,试样尺寸收缩率最低可达2%.采用陶瓷型浸水起模法起模容易,起模后陶瓷型表面光洁,在200℃焙烧温度下抗弯强度较高,为0.361 MPa.这些结果表明,利用SLS技术能够快速、准确地制造出陶瓷型精密铸造所需母模. 相似文献
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覆膜砂SLS过程激光能量分布模型的建立及应用 总被引:1,自引:0,他引:1
针对具有新光束的CO2激光器,建立了铸造覆膜砂SLS过程的激光能量分布模型,在该模型中,综合考虑了新型激光光束的光强分布特点,实际扫描过程中激光与覆膜砂的相互作用,以及扫描速度对激光能量输入的影响等因素.采用Ansys对覆膜砂SLS过程的激光能量分布模型进行计算,利用热像仪对覆膜砂选择性激光烧结过程的表面温度进行测定.经对比计算结果和测温结果,模拟计算与实际测温结果吻合良好.根据模拟计算结果所确定的工艺参数,实际制造出了具有较高精度的三维实体.覆膜砂SLS过程激光能量分布模型为激光快速成形工艺的计算机分析及优化奠定了基础. 相似文献
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针对具有新光束的CO_2激光器,建立了铸造覆膜砂SLS过程的激光能量分布模型,在该模型中,综合考虑了新型激光光束的光强分布特点,实际扫描过程中激光与覆膜砂的相互作用,以及扫描速度对激光能量输入的影响等因素。采用Ansys对覆膜砂SLS过程的激光能量分布模型进行计算,利用热像仪对覆膜砂选择性激光烧结过程的表面温度进行测定。经对比计算结果和测温结果,模拟计算与实际测温结果吻合良好。根据模拟计算结果所确定的工艺参数,实际制造出了具有较高精度的三维实体。覆膜砂SLS过程激光能量分布模型为激光快速成形工艺的计算机分析及优化奠定了基础。 相似文献
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激光直接快速成形是一项融合了快速原型和激光加工的先进制造技术。该技术能在无需工模具的情况下,在计算机三维实体模型的驱动下利用激光熔覆原理逐层堆积加工金属零件。在激光快速成形系统的组成模块中,计算机控制模块在实现系统智能化和自动化方面起着至关重要的作用。该模块可以分为硬件和软件两大组成部分。硬件结构主要由工控计算机、电机和运动控制卡组成,软件结构则为具有图形用户界面的系统应用程序。硬件和软件组成部分协调工作,由此灵活控制整个激光成形系统。 相似文献
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激光制导测量机器人系统设计及运动学分析 总被引:2,自引:0,他引:2
提出新型“光束运动—光靶跟踪”激光跟踪测量方法,并在此方法基础上研究激光制导测量机器人技术,研制并开发一种能够在水平和垂直被测对象表面上运动的小型轮臂复合式激光制导测量机器人系统。该机器人机构融合轮式机构、爬行臂式结构和真空吸附式机构的优点,具有重量轻、体积小、运动灵活和反应快速等特点,可以根据不同被测对象表面特征变换测量模式,利用轮式结构实现机器人在水平被测表面上高速远距离运动,利用爬行臂式和真空吸附式机构实现机器人在倾斜光滑表面上灵活地爬行和转向。建立机器人的运动学模型并对其运动特性进行分析,利用激光跟踪仪和三坐标测量机对研制激光制导测量机器人进行性能测试,试验结果不仅证明了该机器人能够跟踪激光束自动高效地完成被测对象实体测量,同时也验证了所建模型的有效性和正确性。 相似文献
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航空发动机整体叶轮快速制造的试验研究 总被引:3,自引:0,他引:3
选择性激光烧结与铸造技术相结合 ,是快速制造金属零件的有效途径。本文介绍了利用这种技术制作整体叶轮铸造型腔 ,并通过铸造快速获得整体叶轮零件的工艺试验 相似文献
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基于零件切片的选择性激光烧结预热温度控制方法 总被引:5,自引:0,他引:5
选择性激光烧结(Selective laser sintering,SLS)系统是通过加支撑或采用人工调节预热温度的方法来减少成形件的翘曲变形,它劳动强度大、SLS材料浪费多、成形效率低,且预热温度难以精确控制。基于以上情况,提出一种新的控制方法,使预热温度能随零件断面几何形状的变化而自动调节。以华中科技大学开发的SLS设备为研究对象,验证这种新型控制方法的可行性。试验结果和实际应用表明:与原有控制方式比较,根据文中所提出的方法成形的零件表面质量、尺寸精度和形状精度等都有较大幅度改善,并且真正实现了SLS成形过程的自动化。 相似文献
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C.M. Cheah C.K. Chua C.W. Lee S.T. Lim K.H. Eu L.T. Lin 《The International Journal of Advanced Manufacturing Technology》2002,19(7):510-515
The traditional methods adopted for tool design and production in the sheet metal forming industry usually carry a high cost
and long lead time resulting in cost justification problems for short production runs. Rapid tooling (RT) technology is capable
of justifying the cost of tooling suitable for short production runs or design evaluation purposes. In Part 1 of this work,
a new process termed rapid sheet metal manufacturing (RSMM) for the production of soft tooling suitable for prototyping, tool
development, and short production runs was introduced. In addition, an indirect RT method employing rapid prototyping (RP),
rapid soft tooling, and casting for the fabrication of non-ferrous tools was presented. The current work, Part 2, presents
an alternative technique for RSMM whereby metal forming tools are fabricated directly from the RP system via selective laser
sintering (SLS). 相似文献
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Optimizing process parameters for selective laser sintering based on neural network and genetic algorithm 总被引:1,自引:0,他引:1
Wang Rong-Ji Li Xin-hua Wu Qing-ding Wang Lingling 《The International Journal of Advanced Manufacturing Technology》2009,42(11-12):1035-1042
Selective laser sintering (SLS) is an attractive rapid prototyping (RP) technology capable of manufacturing parts from a variety of materials. However, the wider application of SLS has been limited, due to their accuracy. This paper presents an optimal method to determine the best processing parameter for SLS by minimizing the shrinkage. According to the nonlinear and multitudinous processing parameter feature of SLS, the theory and the algorithms of the neural network are applied for studying SLS process parameters. The process is modeled and described by neural network based on experiment. Moreover, the optimum process parameters, such as layer thickness, hatch spacing, laser power, scanning speed, work surroundings temperature, interval time, and scanning mode are obtained by adopting the genetic algorithm based on the neural network model. The optimum process parameters will be benefit for RP users in creating RP parts with a higher level of accuracy. 相似文献
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K.D. Kim D.Y. Yang J.H. Jeong 《The International Journal of Advanced Manufacturing Technology》2006,28(9):923-929
Rapid prototyping (RP) combined with a gravity casting process can provide a suitable substitute with steel tool die casting
for prototyping metal casting. Due to differences between die casting and gravity casting, there are several drawbacks in
RP simulated die casting. This paper is concerned with the development of a new plaster die casting process that combines
pressurization and vibration for prototyping of die castings, and with a plaster die casting machine that has a structure
similar to that of a die casting machine. The machine utilizes an oil cylinder for pressurization and a magnetic actuator
for vibration. A rapid prototyped pattern is made by the laminated object manufacturing (LOM) process to prepare a plaster
mold. In the process, a plunger in the developed machine simultaneously pressurizes and vibrates the molten metal to fill
the plaster mold completely and to facilitate the creation of nuclei in the molten metal, respectively. The developed machine
has produced a prototype of an end clutch cover with remarkable improvement in mechanical properties. 相似文献