共查询到19条相似文献,搜索用时 125 毫秒
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(7)高速电弧喷涂工艺
①预处理工艺
高速电弧喷涂工艺包括工件表面的预处理、喷涂、喷后处理等几个大的步骤。高速电弧喷涂时,高压空气将喷涂材料雾化并高速沉积在工件表面。如果工件表面上带有水分、油脂和灰尘时,喷涂材料微粒与表面之间就会存在一层隔膜,不能很好地互相嵌合。如果表面光滑,微粒也会滑掉或虚浮地沉积,随着喷涂层的逐渐增厚由于内应力增大而脱落。 相似文献
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表面处理加工,通常包括油漆和电镀两大工种(其它如塑料喷涂、离子喷涂、离子注入等也属于表面加工范畴)。经油漆或电镀加工后,金属和非金属制件表面状态发生了很大的变化。由于制件原材料特性和本身的技术要求多种多样,所以油漆和 相似文献
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E.Lugscheider K.Bobzin L.Zhao F.Ernst J.Zwick 《机械工人(热加工)》2007,(5):20-23
冷喷涂工艺具有喷涂材料低氧化性与喷涂过程中基体和粒子表面氧化膜破裂的特性,因此广泛应用于铜焊技术。目前研究中,两种铜焊合金AlSi12和AlSi10Cu4可通过冷喷涂工艺喷涂在6063和3003铝合金上。喷涂参数对粒子速度的影响可通过DPV2000研究。喷涂材料和参数对涂层形成和涂层微观结构的影响已做研究。 相似文献
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镁合金是目前最轻的金属结构材料,具有广阔的应用前景,但耐磨、耐蚀性差却制约着其广泛应用,可通过各种表面改性和表面涂覆技术拓宽其应用范围,介绍了镁合金的应用及其防护技术现状,重点介绍了冷喷涂技术在镁合金表面防护应用现状,分析了镁合金表面金属涂层的发展趋势,提出利用冷喷涂技术制备铝基非晶合金涂层,可望解决缺乏能为镁合金基体提供长效防护的单一涂层难题。 相似文献
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表面热喷涂和车削加工技术的综合运用 总被引:1,自引:0,他引:1
介绍了采用先喷涂后重熔的方法,把合金粉末喷涂在以灰口铸铁为基体的表面,然后用立方氮化硼刀具对其表面车削,提高喷涂表面的加工精度和表面质量以及零件的耐磨性和使用寿命。 相似文献
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A. Sova S. Grigoriev A. Okunkova I. Smurov 《The International Journal of Advanced Manufacturing Technology》2013,69(9-12):2269-2278
In this paper, the application of cold spray (CS) coating deposition technology as additive manufacturing technique is discussed. Absence of material melting during CS deposition permits to obtain deposits with low value of residual stresses and to preserve the phase composition of source material which is a very important advantage. In this paper, the latest developments in the field of cold spray such as micronozzle device and new multimaterial deposition approach permitting to significantly enlarge the potential of cold spray as additive manufacturing technology is discussed. 相似文献
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在冷却塔中为了有效抑制高温烟气的熔融组分和粉尘粘附在内壁上造成腐蚀.必须将高温烟气冷却到期望温度排入集尘器进行再处理.论文以生产还原铁的转底炉为研究对象,采用了对喷流除尘技术和喷雾冷却技术. 相似文献
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高效散热微通道液冷冷板焊接技术及成形工艺研究 总被引:1,自引:1,他引:1
通过分析微通道冷板的结构特点及技术要求,对微通道冷板的焊接方法、焊接工艺进行了分析研究.采用气保护炉钎焊方法,通过巧妙地采用过渡材料与接头设计,既突破了6063铝合金气保护炉钎焊的钎焊性较差的技术难题,满足了钎焊缝密封性要求,又可有效地避免钎料流入微通道.通过焊接工装及接头设计,在合理的工艺及气氛条件下,实现了6063铝合金微通道冷板的整体焊接成形,解决了微通道冷板的焊接技术难题. 相似文献
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CFD simulation of spray penetration with standard KIVA-3V were compared with those using both an ‘original gas jet model’ and a ‘normal gas jet profile model that features a new breakup length formula’ by implementing them in the standard KIVA-3V code. The effects of entrainment coefficient on the spray penetration simulated with the gas jet profile were compared to that simulated with the standard KIVA-3V spray model. The accuracy of the CFD simulation results was estimated by comparing them with available experimental data. Both the standard KIVA-3V spray model and the normal gas jet profile model with the breakup length formula predict well the spray tip penetration up to a gas density of 60 kg/m3. The CFD simulation of spray tip penetration with the standard KIVA-3V predicts better with the ‘original gas jet model’ when the ambient gas density is lower than 60 kg/m3. For higher densities, the normal gas jet profile model with breakup length formula predicts the spray penetration better. 相似文献
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Comparison of experimental and predicted atomization characteristics of high-pressure diesel spray under various fuel and ambient temperature 总被引:1,自引:0,他引:1
Su Han Park Hyung Jun Kim Chang Sik Lee 《Journal of Mechanical Science and Technology》2010,24(7):1491-1499
The aim of this study is to investigate the effects of the fuel temperature and the ambient gas temperature on the overall
spray characteristics. Also, based on the experimental results, a numerical study is performed at more detailed and critical
conditions in a high pressure diesel spray using a computational fluid dynamics (CFD) code (AVL, FIRE ver. 2008). Spray tip
penetration and spray cone angle are experimentally measured from spray images obtained using a spray visualization system
composed of a high speed camera and fuel supply system. To calculate and predict the high pressure diesel spray behavior and
atomization characteristics, a hybrid breakup model combining KH (Kelvin-Helmholtz) and RT (Rayleigh-Taylor) breakup theories
is used. It was found that an increase in fuel temperature induces a decrease in spray tip penetration due to a reduction
in the spray momentum. The increase of the ambient gas temperature causes the increase of the spray tip penetration, and the
reduction of the spray cone angle. In calculation, when the ambient gas temperature increases above the boiling point, the
overall SMD shows the increasing trend. Above the boiling temperature, the diesel droplets rapidly evaporate immediately after
the injection from calculation results. From results and discussions, the KH-RT hybrid breakup model well describes the effects
of the fuel temperature and ambient gas temperature on the overall spray characteristics, although there is a partial difference
between the experimental and the calculation results of the spray tip penetration by the secondary breakup model. 相似文献