化学复合镀Ni—P—Si3N4工艺及其性能研究

通过对化学复合镀Ｎｉ－Ｐ－Ｓｉ３Ｎ４粒子共析量以及镀液稳定性等的研究，获得了制取含Ｓｉ３Ｎ４粒子量高且镀液稳定性好的工艺方法，并讨论了化学复合镀Ｎｉ－Ｐ－Ｓｉ３Ｎ５镀层的耐蚀性能和表面结构。     

铟丝密封件低温密封性能实验研究

针对铟丝密封件,采用法兰-密封件-螺栓密封结构对其进行密封性能的实验研究,测试系统的设计压力范围为0-10 MPa,设计温度为-196℃.基于实验测试结果,探讨了该密封结构的螺栓预紧力、工作压力及温度等与泄漏率之间的关系.     

低温半静密封技术

提出了低温半静密封理念，对低温半静密封的特点、设计机理、密封材料选择进行了论述。论证表明，加力紧固方式及伺服自补偿方式是低温半静密封行之有效的方法。还介绍并分析了业已实用的球面对锥面密封结构、插拔密封结构、端面密封结构等数种低温半静密封结构。     

铟封及其在近贴聚焦象增强器中的应用

本文在介绍铟的有关物理化学性质的基础上讨论了铟作为封接材料所形成真空密封的特点与机理。同时介绍了冷压及热熔两种典型的铟封工艺,最后介绍了采取冷压铟封研制的双近贴聚焦象增强器的封接工艺。     

“Г“型橡胶圈密封结构在大口径弹药包装上的应用

介绍了型橡胶圈密封结构的选型和应用于弹药包装上的效果，分述了材料性能，密封结构及各项试验情况。     

典型异型金属密封的特点及应用

阐述了金属密封的密封机理,指出其密封性能主要受密封结构材料、密封表面质量、密封面宽度、密封比压以及密封表面镀层等因素的影响。介绍了已在工业生产中广泛应用的典型异型金属密封的结构特点、材料、镀层及适用工况,包括金属空心O形圈、金属C形密封环、金属E形密封环、金属U形密封环、金属W形密封环等。     

真空正压转轴密封结构设计与分析

本文重点介绍了作者在实际应用过程中设计的两种真空正压转轴密封结构、性能及特点。利用胶芯弹性盘根作为密封材料设计的新型填料转轴密封结构,在1.3×10-4 Pa～2.5 MPa较宽的压力范围内具有极佳的密封性能,结构具有低摩擦、低漏率、无污染的特性,自润滑性能良好,密封效果持久可靠。     

用于4K级闭式循环制冷机的电磁式可调J－T阀设计

分析了Ｊ－Ｔ阀中气流的流动特性及相关参数的影响，给出了计算程序框图，并对用于４．４Ｋ／０．５Ｗ闭式循环制冷机的Ｊ－Ｔ阀进行了计算，得出了其通道孔径和长度的关系曲线及最佳参数。针对目前普遍采用的可调Ｊ－Ｔ阀的不足之处，提出了一种新型的电磁式可调Ｊ－Ｔ阀，论述了它的结构特点和作用。     

高压低温密封试验研究—试验装置及方法

讨论了在０－１５ＭＰａ的高压下，－１９６℃－＋２００℃温区内，法兰，球头密封结构密封性能的试验方法；介绍了试验装置及试验过程并对部分试验设施进行了讨论最后给出了该试验装置，方法的误差分析及估算。     

多层多级介质过渡线圈整体密封工艺

针对感应线圈承受冲击、过载、浸水试验后可能出现的开裂、断线及密封、绝缘失效等问题，提出了多层多级介质过渡线圈整体密封工艺。就是利用密封接触面及密封胶的热胀冷缩效应，由多种密封材料合理搭配形成介质过渡，通过线孔密封、线圈与壳体槽之间的密封、线圈的层间密封和外层密封等，实现线圈在小体积结构中的密封、强度和绝缘保护。验证试验结果表明：多层多级介质过渡线圈整体密封工艺用于小口径感应装定引信，经过温冲、浸水、锤击等试验后，未出现密封失效、结构开裂、绝缘失效等现象，有效地解决了弹上感应线圈的密封设计、绝缘设计和强度设计的技术难题。该工艺为国内小型感应装定引信信息交联电磁线圈的密封、强度及绝缘设计提供了借鉴。     

小型低温制冷机上的低温密封型式浅析

随着小型低温制冷机在工业、高科技等尖端产业得到越来越广泛的应用，用于其上的低温密封也愈来愈引起人们的重视，低温密封比起普通的密封具有自己独特的要求，该文主要针对小型低温制冷机中的低温密封型式进行简要的说明，并具体给出一些低温制冷机上采用的低温密封实例。     

磁流体-螺旋组合密封对液体介质的密封性能研究

磁流体旋转密封液体时,磁流体与被密封液体间相对运动致使其界面发生稳定性问题,密封性能较差。而螺旋密封在主轴旋转时利用流体动压反输可阻止被密封液体泄漏。为了提高旋转密封性能,设计了磁流体密封与螺旋密封组合的密封结构,搭建了组合密封实验台,理论和实验研究结果表明,该组合密封结构既能解决磁流体密封在较高转速时的失效问题,又能解决螺旋密封在停车及低速时的泄漏问题,实现不同转速下较稳定的密封效果。     

芳纶纤维增强树脂复合材料液氮冷却钻孔试验

芳纶纤维增强树脂（AFRP）复合材料是一种公认的难加工材料,加工中极易出现毛刺、烧蚀等缺陷,目前缺乏对其有效的加工工艺方法。为提高其加工质量,研究了液氮作为冷却介质的AFRP复合材料钻孔试验。在相同切削参数下进行了干式切削和超低温加工对比试验,测量了切削过程中的轴向切削力和孔临近区域的温度,并计算了孔的进出口毛刺面积和分层因子,分析了AFRP复合材料缺陷的成因,探讨了不同加工条件下缺陷的变化规律。结果表明:与干式切削相比,采用液氮超低温冷却加工的切削力升高了约15.2%,切削温度降低了约141.6℃,毛刺面积减少了约24.7%,因切削热产生的烧蚀现象得到抑制,明显改善了AFRP复合材料的加工质量。      

爆炸金属复合材料在低温领域的应用

低温技术的发展推动着爆炸金属复合材料制造技术的进步,从爆炸复合技术原理出发,着重对爆炸金属复合材料在LNG气化器、空气分离设备、液氮生物容器及极地船舶等低温领域应用情况进行了描述,并对未来的市场前景进行了展望。     

Modelling of cohesion and adhesion damage of seal based on dynamic shear rheometer testing

Most current seal designs are based on the volumetric properties of materials and voids. In order to improve seal design, the possibility of introducing mechanistic principles into seal design was investigated. Introducing mechanistic concepts into seal design means that principles such as elasticity and viscoelasticity could be used in terms of stress-strain to explain phenomena such as damage in the seal structure. Two main failure parameters of seals – cohesion failure (fatigue cracking due to ageing of binder and loss of elasticity) and adhesion failure or stripping (occurring between stone to bitumen or bitumen to base) – are investigated using the complex modulus (G ^*) which is one of the viscoelastic parameters of bituminous materials. This paper therefore investigates the testing procedure of cohesion fatigue damage (CFD) and Adhesion Fatigue Damage (AFD) of bituminous seal material using the Dynamic Shear Rheometer (DSR). The CFD and AFD modelling are based on the stiffness reduction principle of materials under the action of cyclic stress. Based on the Lifetime Optimisation Tool (LOT) research programme from Delft University of Technology, a DSR testing procedure and approach was adopted for seals. The tests were performed on 70/100 penetration grade bitumen columns (for CFD) and on stone columns constituted with dolorite glued together with 70/100 penetration grade bitumen (for AFD). It was observed that the model for CFD depends more on stress, while the model for AFD appears to depend more on temperature. This observation agrees with the fact that adhesion damage is more sensitive to temperature change, whereas cohesion damage is more prone to be influenced by applied fatigue stress. The CFD and AFD models provide an indication of non-linear development of the accumulated fatigue damage of seal. This is represented by the modelling of the change of G ^*, as suggested in this investigation.     

往复轴磁性液体密封间隙内磁性液体流动机理的研究

为了解决往复轴磁性液体密封中存在的问题，我们研究了往复轴以不同速度和行程运动时，密封间隙内磁性液体的流动状态。重点研究了：往复轴密封间隙内磁性液体流动机理；往复轴运动所带走磁性液体的量；往复轴磁性液体密封的失效原因；设计往复轴磁性液体密封的新结构．实践表明所设计的新结构在某些应用场合是非常有效的。     

Material Selection for Cryogenic Support Structures

Design specifications for the support structures of low temperature instrumentation often call for low thermal conductivity between temperature stages, high stiffness, and specific load bearing capabilities. While overall geometric design plays an important role in both overall stiffness and heat conduction between stages, material selection can affect a structure’s properties significantly. In this contribution, we suggest and compare several alternative materials to the current standard materials for building cryogenic support structures.     

Delamination growth mechanisms in woven glass fiber reinforced polymer composites under Mode II fatigue loading at cryogenic temperatures

The purpose of this research is to characterize the cryogenic delamination growth behavior in woven glass fiber reinforced polymer (GFRP) composite laminates subjected to Mode II fatigue loading. Mode II fatigue delamination tests were performed at room temperature, liquid nitrogen temperature (77 K) and liquid helium temperature (4 K) using the four-point bend end-notched flexure (4ENF) test method, and the delamination growth rate data for the woven GFRP laminates were obtained. The energy release rate range was determined by the finite element method. Microscopic examinations of the specimen sections and fracture surfaces were also carried out. The present results are discussed to obtain an understanding of the fatigue delamination growth mechanisms in the woven GFRP laminates under Mode II loading at cryogenic temperatures.     

Cryogenic fracture and adiabatic heating of austenitic stainless steels for superconducting fusion magnets

This paper discusses the fracture and the adiabatic heating of austenitic stainless steels that may be used in cryogenic structures for the superconducting magnets of magnetic fusion reactors. Elastic–plastic fracture toughness tests were performed on compact specimens in liquid helium at 4 K. Adiabatic heating was detected by measuring the internal temperature. The effect of test specimen size and side grooving on the cryogenic fracture toughness, and the temperature rise during dynamic crack growth are examined. A size independent toughness parameter results in the case of side-grooved specimens. The effect of inclusion content on the fracture mechanics parameters is also discussed.