共查询到20条相似文献,搜索用时 114 毫秒
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为了加速我国电子行业无铅化进程,利用自行设计的超音速雾化制粉试验装置,研究了过热度对Sn3Ag2.8Cu合金无铅焊锡雾化粉体颗粒形貌的影响。结果表明:通过调整合金的过热度,能够控制雾化粉体中卫星颗粒及异形颗粒的比例;当合金过热度为150℃时,雾化粉体中卫星颗粒和异形颗粒最少,颗粒球形度最好;当合金过热度为100℃时,雾化粉体颗粒球形度较差;当合金过热度为250℃时,雾化粉体卫星颗粒和片状颗粒较多。 相似文献
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水雾化法制粉钢液治炼的氧含量控制是影响雾化效果的重要因素,实践证明,采用CSBA(Ca、Si、Ba、Al合金)新型脱氧合金用于水雾化钢液终脱氧,具有明显降低钢中氧含量、提高雾化效率,改变夹杂物形态作用,可推荐为水雾化钢液终脱氧工艺中首选脱氧合金。 相似文献
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油液的雾化直接影响静电涂油机的喷涂质量,通过静电涂油机的油液雾化实验得到了油液雾化过程的主要指标和影响油液雾化质量的主要因素,根据二者之间的关系建立了静电涂油机油液喷射雾化的数学模型。使用V isual C++面向对象技术和开放图形库,根据所建立的数学模型,模拟了不同电压下油液的静电雾化形态。理论分析和实验研究表明:射流长度随电压的升高和刀梁到钢板距离的减小而越小,雾化角随电压的升高和刀梁到钢板距离的减小先增大后减小。对比不同电压下的油液雾化照片,雾化形态模拟图基本实现了静电喷涂中油液雾化的动态过程,达到了预期的仿真目的。 相似文献
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以气雾化法制备的Inconel718合金粉末为原料,采用激光选区熔化(SLM)技术制备了Inconel718合金,研究了合金的显微组织及性能,并与锻造态合金进行对比。结果表明:SLM成形合金垂直于成形方向的组织呈现明显的带状熔化道,平行于成形方向的组织呈现鱼鳞状熔池的界面结构,晶粒为穿过熔池边界的柱状晶;SLM成形合金平行于成形方向的显微硬度(346 HV)略大于垂直于成形方向(324 HV);与锻造态合金相比,SLM成形合金在质量分数3.5%NaCl溶液中的阻抗曲线半径更大,自腐蚀电位与钝化电位更高,自腐蚀电流密度低2个数量级,耐腐蚀性能更优;当载荷为3~10 N时,成形合金的摩擦因数在0.5~0.8,磨损率在5.4×10-5~14.3×10-5 mm-3·N-1·m-1,均低于锻造态合金。 相似文献
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在不同温度下(1 150,1 200,1 250℃)对氩气雾化Ti-45Al-6Nb-0.3W合金粉末进行放电等离子烧结,研究了烧结温度对合金显微组织和力学性能的影响。结果表明:放电等离子烧结合金由γ相和α2相组成,随烧结温度升高,组织形态由片层和等轴状转变为全片层状,同时晶粒尺寸增大,γ相含量增加;合金密度随烧结温度升高略有增加,硬度变化不大;不同温度烧结合金的压缩性能均优于铸态合金的,1 200℃下烧结合金的室温压缩性能最好,抗压强度、压缩率分别为3 012 MPa,40.8%。 相似文献
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在难加工材料上利用超声波振动钻孔是一种十分有效的加工方法。应用超声波振动在非金属材料上钻削深孔,生产率可提高5~10倍,精度可提高2~3级,大大改善了加工表面质量;在耐腐蚀钢、耐热钢和钛合金以及其它难加工材料零件上钻孔、扩孔、铰孔、用丝锥切制螺纹及用滚子滚螺纹应用超声波振动是十分有效的加工方法;在深孔钻削铝合金时,应用超声波振动,高速钢钻头的耐用度可提高4~45倍。 相似文献
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Christopher B. Williams Joe K. Cochran David W. Rosen 《The International Journal of Advanced Manufacturing Technology》2011,53(1-4):231-239
Cellular materials, metallic bodies with gaseous voids interspersed throughout the solid body, are a promising class of materials that offer high strength accompanied by a relatively low mass. Recent research has focused in the topological design of cellular materials in order to satisfy multiple design objectives. Unfortunately, these design advances have not been met with similar advances in cellular material manufacturing as existing techniques constrain a designer to a predetermined part mesostructure, material type, and macrostructure. In an effort to address these limitations, the authors have developed a manufacturing process chain centered on an augmented three-dimensional printing process. Specifically, metallic cellular materials are made by selectively printing solvent into a bed of spray-dried metal oxide ceramic powder. The resulting green part is then sintered in a reducing atmosphere to chemically convert it to metal. The resultant process has produced maraging steel cellular artifacts featuring a 270-??m wall thickness and angled trusses and channels that are less than 1?mm in diameter. 相似文献
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研究固体粉末激光选择性烧结快速成型的铺粉装置中辊筒的运动轨迹,及烧结粉末在辊筒的推动作用下的流动过程,从理论上推导出粉末流动的剪切面的位置。阐述铺粉过程中辊筒逆向滚动对提高粉末层密度的有利效应,为能够烧结出高质量制品提供了理论依据。 相似文献
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为了解决FeS/Cu粉末冶金复合材料中FeS易团聚以及界面结合差的问题,采用机械合金化技术制备了FeS/Cu复合材料粉末。利用扫描电镜、X射线衍射仪、金相显微镜等对不同球磨时间的质量分数为6%的FeS/Cu合金粉末的混合特性、压制特性及烧结后的力学性能进行检测和分析,结果表明:机械合金化可有效改善FeS颗粒与基体合金粉末的混合均匀性,烧结后材料的密度、硬度均得到提高,FeS和Cu界面结合良好;由于FeS颗粒均匀弥散地分布在铜合金基体中,割裂了基体材料的连续性,反而使复合材料的韧性和压溃强度有所降低。 相似文献
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On the basis of a probabilistic-geometric matrix model of the powder macrostructure, a statistical approach is developed for
describing the frictional-surface microgeometry of powder coatings obtained by high-energy methods, in frictional wear. This
approach permits simulation of the wear of powder coatings and materials. The calculation results are compared with experimental
data. 相似文献
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光谱分析仪是压铸生产过程中用于产品成分质量分析的关键设备,其分析结果是控制压铸工艺参数的依据,对提高压铸铝合金产品质量具有重要的意义。为了建立压铸铝合金成分质量分析的计算机网络系统,研制出一种光谱仪数据采集系统,通过解读打印机输出端口,将光谱仪的分析结果采集到单片机系统中,应用MAX490通信接口设计,实现数据采集系统和成分质量分析系统的远程通信。现场使用和实验表明,该系统具有较高的可靠性和性价比。 相似文献
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大规模生产高质量薄膜产品是今后镀膜设备需要解决的问题。等离子体或离子辅助镀膜现在被广泛应用于高质量膜系生产中并取得了良好的效果,但是主要由于等离子体或离子源的原因,产能不高。介绍了一种新型精密光学镀膜系统和一种新型溅射镀膜系统。新的系统能够优质高效地生产复杂膜系,特别适合大规模生产。 相似文献
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S. P. Burkin A. R. Beketov N. V. Obabkov E. A. Andryukova Ya. A. Brynskikh R. F. Iskhakov 《Journal of Friction and Wear》2009,30(2):87-93
Knowing the coefficients of friction in tool compaction of powders of metals and alloys allows one to rationally design technological equipment for manufacturing powder semifinished products experiencing minimal warping under vacuum or hydrogen sintering. This is of particular significance when consumable electrodes are produced from powders of refractory metals being compacted as rather long fillets that are curved in sintering if any irregularities in the density in the cross section and in the fillet bulk are present. Both well-known and new methods are analyzed for finding the coefficients of friction in powder compaction, in particular in cylindrical containers. Stable and valid measurement results are shown to be unachievable. A new method for experimental determination of the coefficients of friction under powder compaction is described. It consists in comparing the force parameters of one- and two-sided compaction. This method allows finding the coefficient of side pressure and contact friction (on the cylindrical surface of the container) during the formation of briquettes of TsM-2A alloy with different concentrations of plasticizer and solvent. A positive effect of a plasticizer and negative one of a solvent on the coefficient of friction is stated. 相似文献