反应等离子喷涂制备FeAl2O4-Al2O3-Fe复合涂层的研究

以铝粉和氧化铁粉为原料,制备出适于等离子喷涂的复合团聚粉体;并采用反应等离子喷涂技术制备出FeAl2O4-Al2O3-Fe复合涂层,用SEM和XRD分析了复合涂层的组织结构.结果表明反应等离子喷涂得到了以层状基体相FeAl2O4与硬质相Al2O3为骨架,球状Fe相弥散分布于基体上的复合涂层.     

等离子喷涂Al2O3/TiO2纳米陶瓷复合涂层的微观结构及性能

采用等离子喷涂技术制备了不同成分的Al2O3/TiO2纳米陶瓷复合涂层,并利用X射线衍射仪(XRD)、扫描电镜(SEM)、显微硬度计和摩擦磨损试验机等分析测试手段研究了纳米陶瓷复合涂层的微观结构与性能.结果表明:纳米陶瓷复合涂层中Al2O3以α-Al2O3和γ-Al2O3两相共存的形式存在,且γ-Al2O3的含量随喷涂功率的增加而增加,而涂层中的TiO2则以金红石型存在;其微结构为完全熔化区的片状微观组织和部分熔化区的纳米级颗粒共存的组织;等离子喷涂功率和TiO2含量对涂层的硬度和耐磨性能均有显著的影响.     

反应等离子喷涂制备FeAl2O4-A12O3-Fe复合涂层的研究

以铝粉和氧化铁粉为原料，制备出适于等离子喷涂的复合团聚粉体；并采用反应等离子喷涂技术制备出FeAl2O4-A12O3-Fe复合涂层，用SEM和XRD分析了复合涂层的组织结构。结果表明：反应等离子喷涂得到了以层状基体相FeAl2O4与硬质相Al2O3为骨架，球状Fe相弥散分布于基体上的复合涂层。     

等离子喷涂纳米Al2O3/TiO2陶瓷复合涂层高温氧化和热震性能研究

采用等离子喷涂设备在H13热作模具钢表面制备含有不同质量分数TiO2的Al2O3纳米陶瓷复合涂层。采用X射线衍射仪(XRD)、高温氧化试验、热震试验等手段研究等离子喷涂纳米涂层的相组成及其性能。结果表明,等离子喷涂使α-Al2O3转变为亚稳态的γ-Al2O3相,喷涂后涂层中Al2O3由α-Al2O3相和γ-Al2O3相组成,TiO2仍以金红石相存在。纳米AT20涂层比其他涂层具有更好的抗氧化性能;与其他涂层相比,纳米AT13涂层具有最佳的抗热震性能。     

反应等离子喷涂制备FeAl2O4-Al2O3-Fe涂层的性能研究

对反应等离子喷涂制备的FeAl2O4-Al2O3-Fe金属／陶瓷复合涂层的性能进行了研究。结果表明该复合涂层显微硬度存在压痕尺寸效应，并符合Meyer公式，其Meyer指数约为1．75；复合涂层以穿晶断裂为主，断口存在较大起伏，并具有金属拔出机制和韧窝明显的韧性断裂特征，复合涂层韧性较好；涂层结合性能好，结合强度约23．03MPa，要高于普通AT13陶瓷涂层；涂层较致密，孔隙率约为3．33％，低于普通AT13陶瓷涂层。     

多功能微弧等离子喷涂对改进涂层组织和性能的作用

分别采用自行研制的多功能微弧等离子喷涂和传统的Metco 9M等离子喷涂制备了Al2O3＋13％TiO2（简称AT13）涂层，利用扫描电镜、X射线衍射仪以及显微硬度计等分析测试了AT13涂层的组织结构和性能，探讨了枪内中心轴向送粉方式对AT13涂层性能的影响。结果表明，多功能微弧等离子喷涂枪内中心轴向送粉方式制备的AT13涂层粉末粒子熔化充分，涂层主要物相为α—Al2O3、γ-Al2O3、Al2TiO5、ZrO2和CeO2等，显微硬度分布范围为975～1441MPa，平均结合强度为42．7MPa；而Metco 9M等离子喷涂外送粉方式制备的AT13涂层中存在部分未熔纳米AT13粉末粒子，主要物相有α-Al2O3、γ—Al2O3、Al2TiO5、TiO2、ZrO2和CeO2等，显微硬度分布范围为655～946MPa，平均结合强度为19．7MPa。结果显示多功能微弧等离子喷涂采用枪内中心轴向送粉能够制备出更加优异性能的AT13涂层，有利于拓宽AT13涂层在工业领域中的应用。     

等离子喷涂纳米复合陶瓷涂层的组织结构及其形成机理

以Al2O3-13%TiO2(质量分数)团聚体复合陶瓷粉末为材料,采用等离子喷涂工艺在TiAl合金表面制备纳米结构陶瓷涂层.用扫描电镜(SEM)和X射线衍射仪(XRD)分析粉末和涂层形貌、微观结构及相组成,讨论涂层的微观组织形成机理.结果表明:纳米结构复合陶瓷涂层由部分熔化区以及与常规等离子喷涂类似的片层状完全熔化区组成;根据组织结构的不同,部分熔化区又分为液相烧结区(亚微米Al2O3粒子镶嵌在TiO2基质相的三维网状或骨骼状结构)和固相烧结区(经过一定程度长大但仍保持在纳米尺度的残留纳米粒子);等离子喷涂使部分α-Al2O3以及全部θ-Al2O3转变为亚稳态γ-Al2O3;纳米结构复合陶瓷涂层中的完全熔化区、液相烧结区及固相烧结区分别由等离子喷涂过程中纳米团聚体粉末中温度高于Al2O3熔点、介于TiO2熔点到Al2O3熔点之间以及低于TiO2熔点区域沉积获得,纳米结构涂层中不同部分熔化组织源于复合陶瓷粉末中Al2O3与TiO2之间的熔点差异.     

反应等离子喷涂合成Fe-FeAl2O4-Al2O3复合涂层的研究

利用机械团聚法制备了适合等离子喷涂的Fe2O3／Al复合粉体，将此粉体送入等离子焰流，通过复合粉的自反应制备含有Fe、Al2O3和FeAl2O4的复合陶瓷涂层。利用扫描电镜（SEM）、X射线衍射仪（XRD）和透射电镜（TEM）等检测手段对反应等离子制备的复合涂层进行了研究。结果表明：涂层具有以层状陶瓷为骨架，球形金属为弥散相的组织，反应生成涂层的过程是分步进行的，由于反应生成的部分纳米颗粒以及金属的存在，使得涂层的耐磨性和韧性比普通Al2O3涂层有了较大的提高，尤其在高载荷作用下，复合涂层的耐磨性比普通Al2O3提高近两倍。     

激光熔覆等离子喷涂Al2O3陶瓷涂层组织结构研究

研究了45钢表面激光熔覆等离子喷涂Al2O3陶瓷涂层的组织结构、显微硬度及滑动磨损特性.结果表明,等离子喷涂Al2O3涂层的组织呈层片状,层间为机械结合,涂层由α-Al2O3, ZrO2和少量γ-Al2O3组成;激光熔覆Al2O3陶瓷涂层组织为细小枝状晶,由α-Al2O3及少量ZrO2组成.激光熔覆Al2O3涂层的显微硬度较高,滑动磨损时耐磨性明显优于等离子Al2O3喷涂层.     

6063铝合金表面等离子喷涂Al2O3/TiO2纳米陶瓷涂层组织与性能研究

采用等离子喷涂技术在6063铝合金表面喷涂Al2O3/TiO2纳米陶瓷涂层,并利用X射线衍射仪(XRD)、扫描电镜(SEM)、显微硬度计和摩擦磨损试验机等分析测试手段研究了纳米结构陶瓷涂层和传统陶瓷涂层的组织与性能.结果表明:纳米陶瓷涂层中Al2O3以α、γ两相共存的形式存在,且γ-Al2O3的含量随等离子喷涂功率的增加而增加.纳米陶瓷涂层较传统陶瓷涂层的硬度和耐磨性能都有明显的提高.     

Fiber composite structures

A review of some of the unique properties of fiber composites, a summary of some of their more important applications and a look at their future.     

Ceramic composite materials

Conclusion The concept of developing new materials with prescribed properties based on ideas about "building" structures may be realized in creating ceramic composite materials. Creation of heterogeneous composite structures is the main path for achieving high crack resistance (a parameter which mainly governs the operating reliability of structural articles). These structures make it possible to realize energy-consuming processes of the dissipation of work for failure from external forces. The level of properties achieved (crack resistance above 300 N/mm^3/2, strength above 500 N/mm²), and the high permissible operating temperatures make ceramic composite materials irreplaceable for a number of fields of technology. However, the main problems connected with the development of ceramic composites remain unresolved. These are problems for achieving the optimum structure and composition of the interface for components, thermal stability of reinforcing elements, the production cost of both fibers and composite materials, and obtaining highly compact matrices in composite materials reinforced with continuous fibers.Scientific Production Association of the Institute of Aviation Materials. Interbranch Scientific Research Center of Technical Ceramics. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 36–40, February, 1992.     

Ni-Cr合金真空预钎焊金刚石磨粒复合节块界面微结构

在Ni-Cr合金中加入A合金粉制成复合钎料,在加热温度1 050 ℃和保温时间30 min的工艺下进行金刚石磨粒的预钎焊处理试验,在加热温度810 ℃和保温时间4 min的烧结工艺下制备预钎焊磨粒复合节块. 测试预钎焊磨粒的静压强度和复合节块的抗弯强度,并分析预钎焊金刚石、复合节块的界面微结构. 结果表明,复合钎料与金刚石磨粒在预钎焊过程中形成化学结合界面,且对金刚石的热损伤较小;当磨粒浓度范围为10%~50%时,复合节块的抗弯强度均高于常规金刚石节块;预钎焊金刚石与金属胎体在烧结过程中形成冶金结合界面,复合节块界面结合强度高.     

Modelling of composite crystallization

Metal matrix composites(MMCs)have received much attention due to their promising advanced mechanical properties.The aim of this work is to create a micro-macro model of composite crystallization.The developed model is coupled with the process of heat flow in the macroscopic scale,resulting from the heat emission during the nucleation and the growth of grains.Taking into account both of these phenomena,the proposed model is distinguished by a good reflection of reality.Moreover,the presented model assumes that the function of grain density depends on the maximal supercooling and the mass volume of the reinforcement phase particles.The knowledge of the equations,describing the function of grain density depending on the degree of supercooling,is necessary in the,more and more often used,numerical modelling of the casting structure.     

双向复合抽芯机构的设计

针对具有翻盖结构的药用瓶盖,分析了其结构及功能的特殊性,设计了一种新颖的双向复合抽芯机构。机构通过同一斜导柱驱动弯销和滑块,实现侧抽芯滑块和垂直于该滑块滑动方向的型芯在2个相互垂直方向上的顺序抽芯动作。运动分析表明,机构设计合理、工作可靠。     

Ni-P-Nanodiamond composite electroless plating

The effect of nanodiamond content in electrolyte and rotational speed of the stirrer on the deposition rate of coatings,the nanodiamond content in coatings,the microstructure and the micro-hardness of coatings were studied.A self-made pin-on-disk tribo-meter was employed to evaluate the wear resistance of prepared coatings.Results show that the thickness of composite coating decreases with the rotational speed,while the micro hardness of coating and the content of nanodiamond in coating increase with increa...     

复合容器的焊接

针对容器内表面全部实施合金625的堆焊覆层技术条件要求,对于合金625的堆焊覆层,从堆焊覆层工作表面以下2 mm处的铁元素含量应不超过5%,接管法兰与筒体和管帽的部件热处理应在堆焊覆层后和不锈钢内件焊接前进行,筒体与管帽的闭合焊缝焊接和热处理存在问题,采用坡口预边堆焊隔离层,部件焊后热处理后冷态焊接闭合焊缝,图纸要求内壁堆焊层厚度和坡口隔离层厚度不小于3 mm,经焊接实验证明其复合容器堆焊覆层最小厚度应为5 mm,用焊接工艺评定验证了该结构的各项性能指标均满足标准和规范要求。     

Electrodeposited composite tin-lead coatings

The structures, morphologies and composition of tin-lead alloy electrodeposits, with and without dispersed silicon carbide particles, were studied using a rotating cathode. The incorporation of silicon carbide particles was found to reduce the rate of reduction of tin ions.