共查询到20条相似文献,搜索用时 109 毫秒
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简要分析了选择性激光烧结的成形机制及其工艺和材料影响因素。详细分析了青铜一镍粉末直接选择性激光烧结的材料组分以及磷元素对烧结成形质量的影响。具体讨论了粉床温度、粉层厚度、激光功率以及激光扫描速率和方向等工艺参数对烧结件致密度和强度等机械性能的影响 相似文献
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青铜-镍粉末直接选择性激光烧结的研究 总被引:2,自引:0,他引:2
简要分析了选择性激光烧结的成形机制及其工艺和材料影响因素。详细分析了青铜-镍粉末直接选择性激光烧结的材料组分以及磷元素对烧结成形质量的影响。具体讨论了粉床温度、粉层厚度、激光功率以及激光扫描速率和方向等工艺参数对烧结件致密度和强度等机械性能的影响。 相似文献
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工艺参数对316不锈钢粉末激光烧结温度场的影响 总被引:1,自引:1,他引:0
以有限元分析软件ANSYS为平台,对316不锈钢粉末激光烧结温度场分布进行了数值模拟.在考虑了材料的热物性参数随温度变化以及相变潜热等非线性情况下,建立了选择性激光烧结(SLS)三维有限元模型,利用ANSYS参数化设计语言APDL控制激光热源的热流密度、移动速度以及扫描路径,研究了工艺参数(激光功率、扫描速度、预热温度)对316不锈钢金属粉末成型过程中熔池及温度场分布产生的影响.模拟结果与前人文献实验结果相吻合,表明可以利用本模型对工艺参数进行优化,为实验工艺参数选取提供了理论依据. 相似文献
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描述了激光选择性烧结金属粉末快速成形设备的粉末供给和铺平压实系统及动作,探讨了烧结过程参数对烧结质量的影响,粘结剂含量、孔隙率和缺陷尺寸与烧结件压缩强度之间的关系,并指出影响激光选择性烧结的重要因素是烧结粉末的特性、激光参数的设置等。 相似文献
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激光选区熔化是一种成形难加工金属的方法,文中以90W-7Ni-3Fe为研究对象,分别考虑材料在粉末和实体状态下的物性参数,建立温度场有限元模型,模拟成形过程中的温度场,研究了不同工艺参数下的熔池尺寸、温度梯度、冷却速率变化等. 温度场分析表明,熔道中心温度超过了钨的熔点,粉末充分熔化,而熔道搭接处温度仅超过镍铁熔点,钨颗粒并未熔化,因此在相邻道之间区域是以液相烧结方式形成. 同时,设计了相应参数的工艺试验,发现增大能量输入,可以使液相填充更加充分,成形件致密度提高. 相似文献
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采用选择性激光烧结(Selective laser sintering,SLS)和选择性激光熔化(Selective laser melting,SLM)工艺,分别进行了铁基合金粉末的快速成形试验,对比分析了SLS与SLM成形机理、相应的工艺参数以及它们对测试件成形过程、金相组织与力学性能的影响。结果表明:由于成形机理不同,相对于SLS技术,采用SLM能够制造高致密度、组织均匀、力学性能良好的金属零件,但容易出现翘曲变形、裂纹与球化现象。通过制定合适的材料与工艺参数能够避免上述缺陷。 相似文献
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IGNITING SHS BY LASER AND ITS APPLICATION TO SELECTIVE LASER SINTERING OF METALLIC POWDER MATERIAL 总被引:1,自引:0,他引:1
Y.S. Shi S.C. Chen X.L. Lu S.H. HuangState Key Laboratory of Plastic Forming Simulation Die & Mould Technology School of Material Science Engineering Huazhong University of Science Technology Wuhan China 《金属学报(英文版)》2004,17(5)
1.IntroductionSelective laser sintering (SLS) is one of typical rapid prototyping (RP) technology. SLS adopts the idea of a delamination manufacturing, which is not limited by complicated degree of part shape and not needs any frock & mould, to directly fabricate three dimension (3D) solid parts with powder materials. Theoretically, any powder materials, which can felt each other after they are heated, may be SLS materi-als. Range of SLS materials have covered with polymer powder, cerami… 相似文献
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Processing and mechanical properties of porous 316L stainless steel for biomedical applications 总被引:2,自引:0,他引:2
Montasser M. DEWIDAR Khalil A KHALIL J. K. LIM 《中国有色金属学会会刊》2007,17(3):468-473
Highly porous 316L stainless steel parts were produced by using a powder metallurgy process, which includes the selective laser sintering(SLS) and traditional sintering. Porous 316L stainless steel suitable for medical applications was successfully fabricated in the porosity range of 40%-50% (volume fraction) by controlling the SLS parameters and sintering behaviour. The porosity of the sintered compacts was investigated as a function of the SLS parameters and the furnace cycle. Compressive stress and elastic modulus of the 316L stainless steel material were determined. The compressive strength was found to be ranging from 21 to 32 MPa and corresponding elastic modulus ranging from 26 to 43 GPa. The present parts are promising for biomedical applications since the optimal porosity of implant materials for ingrowths of new-bone tissues is in the range of 20%-59% (volume fraction) and mechanical properties are matching with human bone. 相似文献
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Investigation of laser consolidation process for metal powder by two-color pyrometer and high-speed video camera 总被引:2,自引:0,他引:2
This paper deals with the measurement of surface temperature on metal powder during the laser consolidation process with two-color pyrometer. Additionally, the aspect of selective laser sintering (SLS) and selective laser melting (SLM) of metal powder is visualized with high speed video camera. As a result, the surface temperature during the laser irradiation was ranged 1520–1810 °C and the consolidation phenomena was classified according to the melting point of metal powder. The metal powder at the heating process cohered intermittently to the melt pool although the laser beam was continuously irradiated to the powder surface. 相似文献
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A powder metallurgy (PM) process to fabricate alumina parts through indirect selective laser sintering (SLS) of spherical alumina-polyamide composite powder is presented. The PM process includes powder production, SLS, debinding and furnace sintering. Three different strategies are investigated in order to improve the density of the final alumina parts: laser remelting, warm isostatic pressing (WIP), and different infiltration techniques which use alumina containing suspensions: pressureless infiltration and infiltration under pressure (i.e. squeeze infiltration). Furthermore, microstructural and geometrical changes which occur during the PM process are investigated. 相似文献
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应用结合的选择性激光烧结和冷等静压技术快速制造金属零件。使用有限元方法预测零件的最终尺寸并降低成本;使用Drucker-Prager-Cap模型在ABAQUS软件中实现对选择性激光烧结零件的冷等静压过程的模拟。金属粉末的性质通过冷等静压实验测量。结果表明:橡胶包套和摩擦因数对零件的形状和尺寸影响很小;零件只有均匀收缩,没有明显的形状扭曲。实验与模拟结果符合得较好,这表明Drucker-Prager-Cap模型是模拟冷等静压过程的有效模型;通过模拟可以为选择性激光烧结零件的冷等静压成形过程提供有益的指导。 相似文献
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Fangxia Xie Xinbo He Shunli Cao Xuanhui Qu 《Journal of Materials Processing Technology》2013,213(6):838-843
Selective laser sintering (SLS) technique is capable of rapidly fabricating customized implants with porous structure. A simple encapsulation process was developed to coat 316L stainless steel (316L SS) powder with ethylene-vinyl acetate copolymer (EVA). Subsequently, porous 316L SS was prepared by SLS preforming of EVA-coated metal powders, debinding and sintering in hydrogen atmosphere. The effects of processing parameters on pore characteristics and mechanical properties were analyzed. The results indicate that the porosity of green body mainly depends on laser energy density, while the pore features and mechanical properties of sintered specimens are largely dominated by sintering temperature. After sintering at 1100–1300 °C, the average pore size and porosity are 160–35 μm and 58–28%, respectively. In addition, the elastic modulus and compressive yield strength are 1.58–6.64 GPa and 15.5–52.8 MPa, respectively. It is revealed that the pore structural parameters and mechanical properties of the as-sintered porous 316L SS can be controlled readily to match with those of cancellous bone by modification of SLS processing parameters and subsequent sintering temperature. 相似文献
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Y.S.Shi S.C.Chen X.L.Lu S.H.Huang 《金属学报(英文版)》2004,17(5):694-704
How to directly fabricate metallic functional parts with selective laser sintering (SLS) process is a potential technique that scientists are researching. Existent problems during directly fabricating metal part by use of SIS are analyzed. For the sake of solving the problems, a new idea of adding self-propagating high-temperature synthesis (SHS) material into metallic powder material to form new type of SIS metallic powder material is put forward. This powder material can release controllable amount of heat during its interaction with the laser beam energy to reduce the requirement to laser power during directly sintering metallic part, to prolong the time of metallic liquid phase existing, and to improve the intensity and accuracy of SIS part. For this reason, SHS material‘s interaction with the CO2 laser beam energy is researched, which proves that CO2 laser beam energy may instantly ignite SHS reaction. On the basis of the above-mentioned researches, the effect of sintering the metal powder material mixing SHS material with CO2 laser is also researched,which shows: there is an optimal blending ratio of various material in the new metallic powder material. Under the optimal blending ratio and SIS process parameters, this new metallic powder material can indeed release amount of heat and SHS reaction may be controlled within the laser sintering. This research result makes it possible that the metallic part is directly sintered with small CO2 laser (less than 50W), which may greatly reduce the volume, cost and running expenditure of SIS machine, be propitious to application. 相似文献
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The paper describes a new powder composition specially developed for selective laser sintering (SLS). The aim is to obtain a ferro powder that can be sintered without need for a (sacrificial) polymer binder and that results in quasi dense parts that do not need any post-processing like furnace sintering, infiltration or HIP. The powder is a mixture of different types of particles (Fe, Cu, Ni and Fe3P). The composition and mixture ratio are justified by using phase diagrams. The powder has been tested using an own developed Nd: YAG SLS machine. The influence of process parameters (laser power, scan velocity, scan spacing and scan strategy) and the microstructural characteristics have been investigated. Attention is devoted to the binding mechanism (liquid phase sintering, through melting) and to the quality of resulting parts (density, balling effect,…). 相似文献