基于自蔓延高温合成(SHS)的涂层技术

综述了几种利用自蔓延高温合成(SHS)反应制备涂层的技术,包括反应热喷涂、SHS离心铸造涂层、SHS熔铸涂层以及反应铸渗涂层.介绍了它们的工艺过程、工艺特点、适应的反应体系以及涂层性能.这些基于SHS反应,用于制备耐磨耐蚀陶瓷或金属陶瓷涂层的涂层技术,充分利用SHS技术本身具有的节能、工艺简单、产物纯度高等优点,显示出了很强的竞争优势.     

不同喷涂工艺对Cr~(3+)掺杂Al_2O_3陶瓷涂层相结构及发光性能影响研究

通过火焰喷涂工艺和等离子喷涂工艺制备了Cr~(3+)掺杂Al_2O_3陶瓷涂层。采用扫描电镜、X射线衍射、荧光光谱仪等方法表征了涂层的微观形貌、孔隙率、相结构及发光性能等。对比两种不同工艺制备的Cr~(3+)掺杂Al_2O_3陶瓷涂层性能结果表明:等离子喷涂制备的涂层形貌、颗粒熔化状态、厚度均一性均优于火焰喷涂涂层,但火焰喷涂工艺涂层的发光性能远优于等离子工艺涂层,其原因是火焰喷涂制备的涂层中Al_2O_3粒子的熔融状态更差,保留了更多的α-Al_2O_3相,未熔粒子部分将以喷涂原粉中稳定的α-Al_2O_3结构存在涂层中进而影响其光学性能。     

制备工艺方法对 NiCrFeMo 涂层组织和性能影响研究

采用等离子喷涂、 超音速火焰喷涂和冷喷涂工艺制备了 NiCrFeMo 涂层, 并对涂层的金相性能、 不同基体 材料下涂层的结合性能、 不同温度下涂层的耐磨性能进行了检测。 实验结果表明： 采用冷喷涂工艺制备的涂层孔 隙率最低, 对应涂层的结合强度最高, 但冷喷涂工艺制备的涂层对基体材料较为敏感, 而超音速火焰喷涂和等离 子喷涂受基体材料影响不大。 在室温下, 冷喷涂涂层显示出较优的耐磨性能, 在高温下超音速火焰喷涂涂层显示 出较优的耐磨性能。     

涂层包装带工艺开发与研制

对涂层包装带的涂层方式、工艺开发及涂层工艺要求进行了阐述，重点时辊涂工艺生产包装带的技术要点进行了分析。     

喷涂工艺对MCrAlY涂层组织影响

采用超音速、爆炸喷涂工艺制备钢铁炉辊用MCrAlY涂层,借助XRD、SEM和EDS等手段分析了涂层组织。结果显示：超音速制备涂层中Cr元素含量比粉末成分偏高,Al、Y元素降低,可能在喷涂过程中元素烧损,形成的氧化物在喷涂沉积过程被吹飞,未沉积到涂层中。XRD分析结果显示涂层由Co基固容体、Al,Co、Cr7C3、TaC等相组成。涂层致密,孔隙率低,显微硬度大,结合强度高。相对超音速工艺制备涂层,爆炸喷涂工艺制备的涂层中除铝元素外,分布较均匀,涂层致密度较低,涂层相对显微硬度较高,结合强度二者一致。     

溶液前驱体等离子喷涂热障涂层结构研究

以锆盐和钇盐水溶液为原料,采用常规等离子喷涂工艺和超音速等离子喷涂工艺制备出了均有垂直裂纹结构的SPPS热障涂层,利用扫描电镜(SEM)、显微硬度计和实验电阻炉,研究了SPPS涂层的微观结构、显微硬度及其高温热循环性能。结果表明:相比于常规等离子喷涂,超音速等离子喷涂工艺具有更高的能量和粒子飞行速度,在相同送料速率下,喷涂距离为50mm时SPPS涂层沉积速率为前者在喷涂距离为30mm时的2.3倍,SPPS涂层沉积致密度和显微硬度也高于前者,喷涂距离对SPPS涂层微观结构影响也相对较小,采用超声速等离子喷涂可在更大工艺范围内制备出性能较好的SPPS涂层。采用常规等离子喷涂工艺和超音速等离子喷涂工艺制备的SPPS涂层分别在1100℃下热循环1270h和970h后涂层完整。     

刀具涂层材料的现状与发展趋势

本文介绍涂层刀具的性能特点、涂层材料和涂层工艺，阐述刀具涂层材料的发展趋势。     

WC基涂层材料和制备工艺对其组织结构与性能的影响

本文采用超音速火焰(HVOF)喷涂工艺制备了二种微米结构WC-10Co-4Cr及一种纳米结构WC-12Co金属陶瓷复合涂层;采用SEM、XRD等分析了涂层的组织结构;测量了涂层的显微硬度、孔隙率及开裂韧性;采用超声振动空蚀装置研究了涂层的抗空蚀性能,探讨了涂层空蚀机理。结果表明:由燃油型HVOF工艺制备的纳米WC-12Co涂层孔隙率最低,组织最细小,开裂韧性明显高于燃油型和燃气型HVOF工艺制备的微米WC-10Co-4Cr涂层;燃油型HVOF工艺制备的微米结构WC-10Co-4Cr涂层显示了最优异的抗空蚀性能,空蚀率仅为纳米WC-12Co涂层的1/3左右。     

高温可磨耗复合梯度涂层喷涂工艺研究

按照常压等离子喷涂工艺路线,选择合理的喷涂工艺参数和复合喷涂材料的配比,使用常压等离子喷涂设备在发动机结构件上制备出了高温可磨耗复合梯度封严涂层。对该涂层显微组织、EDS微区成分、涂层组织抗氧化性和涂层氧化增重曲线的测试分析表明,涂层的结构和性能符合相关标准,制备的涂层达到了高温可磨耗封严涂层的使用要求,并已得到实际应...     

20g钢表面La0.7Ca0.3CrO3涂层的结构特征

用溶胶-凝胶法在碳钢基底上制备了钙钛矿型稀土复合氧化物涂层(La0.7Ca0.3CrO3),通过扫描电镜(SEM)和X射线衍射(XRD)等手段对不同工艺所获得的涂层表面形貌、相组成进行了分析,讨论了工艺参数对涂层结构的影响.结果表明,涂层由La0.7Ca0.3CrO3单相组成,在基底与陶瓷涂层之间存在氧化铁过渡层.工艺参数对涂层形貌和相组成影响很大,随前驱体溶液浓度及pH值增大涂层变得疏松,随浸渍次数增多涂层厚度和致密度均增加.     

彩涂涂机轴承改型分析及应用

介绍了攀钢彩涂生产线辊式涂机的工作原理和存在的问题,结合生产工艺和现有设备,着重阐述了对涂辊轴承改型的分析计算,优化了涂机工艺参数,对降低涂层厚度产生了较大的经济效益。     

Improving Wear Resistance of the Ni-base Thermal Spray-Welding Coating Using Rare Earths

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Influence of Coating Granulation Process on Iron Ore Sinter Quality and Productivity

For better blast furnace performance, there has always been a need for better quality raw materials like sinter, lump ore, and pellets. Among these raw materials the usage of sinter in blast furnace is at higher side compared to other iron bearing materials. As the quality of sinter product improves, its usage in blast furnaces also increases. Iron ore fines are the main source for sinter making. To improve the sinter properties it is necessary to provide good quality of iron ore fines. Due to depletion of high grade iron ore resources, goethite and limonitic ore content in iron ore fines is expected to increase gradually. Usually limonitic and goethite ore are associated with higher alumina and LOI. The conventional sintering process is one of the well established processes for high quality hematite ore. It does not fully respond to the low grade iron ore associated with goethite and limonite. This has led to deterioration in sinter properties and productivity. In recent years the improvement in the quasi‐particle structure with the granulation process is an effective method for improving sinter quality and productivity. To improve the sinter quality and productivity for low grade iron ore fines, different granulation processes like the conventional one, and other two advanced granulation processes like coke breeze, and flux & coke breeze coating granulation were studied in detail by conducting laboratory pot grate sintering experiments. From the test results it was found that sinter productivity, physical and metallurgical properties of the sinter improved with flux & coke breeze coating granulation process compared to conventional and coke breeze coating granulation process. Proper selection of the granulation time is very important to achieve the desired sinter properties. In the present work detailed laboratory experiments have been carried out by varying the coating time from 30s to 110s to study the influence of flux & coke breeze coating granulation time on mineralogy, productivity, physical, and metallurgical properties of sinter. With a coating granulation time of 50s, higher productivity, higher yield, and stronger sinter (higher T.I) with lower RDI and ‐5mm size sinter were achieved.     

超音速火焰喷涂NiCrAlY-Y2O3金属陶瓷涂层抗结瘤性能研究

以NiCrAlY和Y2O3粉末为原料通过两种工艺分别制备出团聚烧结和混合型NiCrAlY-Y2O3金属陶瓷粉末,研究了该两种用于热喷涂给料粉末的颗粒形貌及粉末性能.使用该两种粉末及一种商用CoCrAlY-Y2O3通过超音速火焰喷涂(HVOF)在不锈钢基体上制备厚度约为100um的涂层。研究了涂层的孔隙率及抗热冲击能,将四种热喷涂涂层在高温下与MnO,Fe3O4及含锰碳钢进行接触反应后对它们的抗结瘤性能进行了相对的静态比较,结果表明,团聚烧结NiCrAlY-Y2O3涂层具有较好的抗锰氧化物的结瘤,而抗铁氧化物结瘤性能差。团聚烧结金属陶瓷涂层比混合型陶瓷涂层具有更好的抗氧化物结瘤性能。     

A sintered bearing with a plastics coating and a compensating reservoir

Summary The results are presented of a laboratory study of a new type of sintered bearing with a plastics coating and a compensating reservoir. The properties of this bearing combine the ability, characteristic of porous materials, to regulate the lubricant supply to the surface depending on temperature, a low coefficient of friction, and the high-load-carrying capacity of thin-layered plastics coatings, with only a slight quantity of lubricant. The proposed reversed pair arrangement improves the operation of the bearing and prolongs its life. The lubrication of the bearing requires no attention during the whole operating life of the latter.     

提高硬质合金拉丝模寿命的研究进展

如何提高使用寿命是硬质合金拉丝模研究的重要方向.而模芯材质、内孔涂层和内孔结构设计是影响硬质合金拉丝模寿命的重要因素.由于硬质合金拉丝模存在耐磨性较差、寿命较短的缺点,本文从基体材质优化、涂层处理、内孔结构优化三个方向,介绍了提高其寿命的研究进展.通过以下方法可以有效地提高硬质合金拉丝模的使用寿命:低钴超细晶硬质合金,...     

WC复合镀层耐腐蚀性能研究

采用复合电沉积工艺制备了Ni-WC复合镀层,通过SEM、EDS和金相显微镜对其表面和断面形貌进行了观察,并借助电化学手段研究了Ni-WC复合镀层在3.5%NaCl腐蚀液中耐蚀性能。结果表明:WC微粒随着电沉积过程逐步埋入复合镀层并均匀分布,镀层与基体间结合良好,在3.5%NaCl腐蚀液中,复合镀层比纯镍镀层相比,腐蚀电位正移而腐蚀电流减少,耐腐蚀能力得到提高。     

Wear resistance in ceramic silicon nitride cutting tools bearing continuous or discrete titanium nitride coatings

Measurements have been made on the wear resistance of ceramic cutters based on silicon nitride and bearing titanium nitride coating during the continuous machining of ShKh15 steel. The coatings were deposited by cathode sputtering. Use was made of continuous coatings and discrete ones in the form of ordered fragments. The continuous TiN coatings raise the wear resistance by a factor of 1.7, while the factor is 2.2 for the discrete TiN coatings. The performance of the tool is also improved in the case of the discrete coatings as the cutting speed and feed can be raised by comparison with tools with continuous coating.     

镀Zn-5%Al-Re钢丝生产线工艺研究

Galfan镀层与热镀纯锌层相比具有明显的优点,是将来镀层的发展方向。文章介绍了Galfan镀层工艺流程,探讨了“一次浸镀法”的合金成分的选定以及电解助镀和表面处理等生产工序。     

钛白粉无机包膜优化研究

表面处理是金红石钛白粉生产的关键工序,本文研究了不同工艺条件对TiO2包膜效果的影响,以包膜后的分散性、亮度、Tcs等应用性能的变化为依据确定相应的工艺参数。