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指出磷化膜的外观会受磷化喷淋设备的影响,阐明了磷化膜的点状、条状、发蓝、发黄等缺陷与磷化液流量、压力、喷淋状态诸因素的关系,提出喷淋磷化设备设计或改造时管道或喷嘴的合理分布意见,并介绍了喷淋磷化设备维护方面的几点经验。 相似文献
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钢铁的磷化工艺技术(Ⅲ) 总被引:1,自引:0,他引:1
7 低温、常温磷化工艺7.1 低、常温磷化工艺特点低温磷化是指温度为 35~ 4 5℃磷化 ,而常温磷化是指不加热在自然室温条件下的磷化 ,通常为 1 0~ 35℃。低常温磷化绝大部分以轻铁系、Zn系磷化为主。也有在 Zn系磷化液中加入 Mn、Ca、Ni等改性剂 ,习惯上仍称为 Zn系磷化。低、常温磷化工艺 ,一般都需要有表面调整工序 ,该工艺适用于浸渍或喷淋施工 ,用作油漆涂装底层。溶液的游离酸与总酸度比值一般为 1∶ ( 30~50 )。低、常温磷化得到的膜层较薄 ,结晶细密 ,但耐蚀性及耐热性不如高、中温磷化膜。它的优点是不需加热 ,节约能源 ,生… 相似文献
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分别介绍了金属表面前处理和隧道式喷淋磷化工艺流程。说明了表面活性剂的脱脂类型——酸性脱脂、碱性脱脂和溶剂型脱脂的特点以及隧道式喷淋脱脂——预脱脂、隧道式喷淋磷化、磷化后洗涤和钝化等工艺常见的问题。同时对其它磷化方法如高压喷雾磷化、浸渍磷化和喷雾式磷化,喷淋设备及磷化脱脂液过滤装置和循环系统进行了介绍。 相似文献
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介绍了一种阳离子为锌和锰的磷化液,可以满足阴极电泳配套性要求的无镍磷化工艺。通过对磷化膜膜重,溶出率、结晶形貌、膜成分、电泳后漆膜附着力、抗,中击、耐腐蚀等性能进行比较分析,结果表明在锌离子1.2g/L、锰离子O.8g/L、磷酸根16.0g/L的磷化工艺条件下形成的磷化膜性能指标符合阴极电泳配套要求,与常规锌锰镍系磷化膜基本无差别,性能指标远远高于高锌磷化工艺磷化膜。磷化膜的主要性能指标:P比为85.53%,膜重为3.2g/m2,晶型呈粒状,晶粒大小为3~4μm,磷化膜电泳溶出率为3.7%,附着力和冲击试验均合格,磷化膜与电泳漆复合膜(厚度为20.3μm)盐雾试验500h,单边扩展小于1mm,表面无气泡。 相似文献
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开发了一种新型的无磷转化液,通过浸渍或喷淋的方式在样板表面镀上一层氧化锆/硅烷复合膜层,利用SEM、EDS和XRD等测试手段对膜层的表面形貌和物相结构进行分析,结果发现膜层为非晶结构;通过对电泳后的样板进行附着力、耐冲击、耐腐蚀性等试验,得出复合膜层的主要性能指标为:附着力试验合格、冲击无裂纹、500h中性盐雾试验后漆膜单边腐蚀宽度约为1him,表面无起泡现象。通过与磷化液的对比试验发现,该复合膜具有与磷化膜相当甚至超过磷化膜的耐腐蚀性能。 相似文献
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介绍了一种应用于电泳涂装前处理过程,满足无镍要求的锌锰系磷化工艺。采用SEM(扫描电子显微镜)、XRD(X射线衍射)等手段研究比较了无镍磷化膜与普锌磷化膜的性能,并通过各种测试手段研究了磷化膜与阴极电泳的配套性能。结果表明:无镍磷化优于普锌磷化,并能够满足阴极电泳配套的技术要求,此无镍磷化膜结晶晶体呈粒状,晶粒尺寸为2~5μm,磷化膜质量在1.5~3.0 g/m2之间,"P比"大于85%,阴极电泳溶出率较低,可以通过抗冲击性能,耐盐雾性能测试。实际应用显示,该工艺具有稳定的工艺性能和膜层性能,可以在阴极电泳涂装前处理中推广使用。 相似文献
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A variety of Si-C-Al-N-(O) ceramics with different AlN and SiC contents were prepared by pyrolysis of Si-Al-C-O precursors at 1700°C in nitrogen. In those ceramics containing small amounts of aluminum, a new 27 Al MAS NMR peak at 134.3 ppm was found. The existence of this peak is discussed in relation to recent findings in aluminum-containing complex ceramic systems. 相似文献
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分光光度法测定水中单核铝与多核铝的研究 总被引:2,自引:0,他引:2
研究了将水样中的多核铝转化为单核铝的预处理方法,即加入适量(1 3)HCl,于40℃水浴中加热10min,便可破坏水样中的羟基聚合铝,使单核铝游离出来.采用Al(Ⅲ)-CAS-CPB-NP显色体系测定铝.结果表明,在混合表面活性剂CPB-NP存在下,铝与铬天青S在HAc-NaAc介质中形成蓝紫色配合物,其最大吸收波长为625nm,表观摩尔吸光系数为9.41×104L/(mol·cm),线性范围为0~0.12mg/L.该法可用于水样中单核铝与多核铝的测定. 相似文献
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采用盐酸、硝酸溶样,硫酸冒烟分解样品,以氢氧化钠沉淀分离铁等元素,采用氟盐取代EDTA滴定法测定铝铁合金中的铝含量。铝的回收率在99.0%~101.0%,分析结果准确可靠。 相似文献
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为得到具有高活性多孔铝粉和氢化铝共存的混合体系,在常压下采用格氏试剂法对普通铝粉进行活化,通过半固相反应得到高活性微米多孔铝粉,用红外光谱、X射线衍射、扫描电子显微镜、静态氮吸附等方法对样品进行了表征,通过氧化还原滴定法测试了微米多孔铝粉的活性。结果表明,制备所得样品的主要成分是铝粉,同时还有部分AlH3;样品具有多孔结构,粒径多数分布在30μm左右,不仅具有孔径在2~10nm之间的中孔,还存在孔径分布在1nm以下的部分微孔结构;总孔体积为普通铝粉的5~7倍,比表面积为普通铝粉的2~3倍,样品平均活性含量达到92.83%。这种含有AlH3的高活性微米多孔铝粉混合体系在含能材料领域有很大的应用价值。 相似文献
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In order to investigate the phase evolution and microstructure of aluminum containing carbon composites,- 195 graphite flake and ≤0. 074 mm aluminum powders( Al 99%,in mass,the same hereinafter) were used as main starting materials. The mixture with 1 ∶ 1of graphite and aluminum was well mixed with additional 15% phenolic resin and then shaped in a hydraulic machine. The specimens were first dried at 250 ℃ for12 h,and then graphite-embedded fired at 800,1 000,1 200,1 400,and 1 600 ℃ for 3 h,respectively. XRD and SEM were used to characterize the phase compositions and section microstructure. The results show that at800 ℃ aluminum powder melts and reacts with carbon in resin forming granular Al4C3 at the edge of graphite;at 1 000 ℃,Al4C3 increases in amount and grows in volume,and AlN commences to form; at 1 200 ℃,some Al4C3 grows to tabular shape,and other Al4C3 nitridizes forming fibrous AlN; at 1 400 ℃,Al4C3 decreases because it is nitridized or oxidized forming fibrous AlN or Al2O3; at 1 600 ℃,Al4C3 disappears,AlN or Al2O3 gets big and coarse. 相似文献
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以钢铁和铝及铝合金为基材,研究了锌离子浓度对酸度、磷化转化膜的外观、钢铁件硫酸铜点滴时间、铝件氢氧化钠点滴时间的影响,最终获得了致密、耐腐蚀的铝及铝合金磷化膜。 相似文献
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Mamoun Medraj Robert Hammond William T. Thompson Robin A. L. Drew 《Journal of the American Ceramic Society》2003,86(4):717-26
The importance of aluminum nitride (AlN) stems from its application in microelectronics as a substrate material due to high thermal conductivity, high electrical resistance, mechanical strength and hardness, thermal durability, and chemical stability. Yttria (Y2 O3 ) is the best additive for AlN sintering. AlN densifies by a liquid-phase mechanism, where the surface oxide, Al2 O3 , reacts with Y2 O3 to form an Y-Al-O-N liquid that promotes particle rearrangement and densification. Construction of the phase relations in this multicomponent system is essential for optimizing the properties of AlN. The ternary phase diagram of the AlN–Al2 O3 –Y2 O3 was developed by Gibbs energy minimization using interpolation procedures based on modeling the binary subsystems. This paper aims at testing the resultant understanding experimentally at selected compositions using in situ high-temperature neutron diffractometry. These experimental results agree with the thermodynamic calculations of AlN–Al2 O3 –Y2 O3 . The ternary phase diagram has been constructed for the first time in this work. High-temperature neutron diffractometry has permitted real time measurement of the reactions involved in this ternary system, especially to determine the temperature range for each reaction, which would have been difficult to establish by other means. 相似文献