NEPE推进剂/衬层粘接界面XPS表征

运用XPS分析手段表征了NEPE推进剂/衬层粘接界面的化学组成和老化历程,通过研究界面区的化学组成及分布,得出了界面区各位置及老化前后主要组分的变化;探讨了界面老化过程中元素结合能变化与老化失效的关系,认为界面区域中结合能是286～287 eV的羟基和结合能是401～402 eV的N活性基团的含量降低,以及硝基的分解是粘接界面失效的主要原因.     

航天器电子产品搭接电阻的控制与测量

介绍了电磁兼容性技术在航天器电子产品中的应用,针对产品建造规范中搭接电阻和屏蔽的设计,从电气和机械设计、工艺各环节的设计以及产品实现等几个方面提出了搭接电阻的控制方法。同时,给出了为实现电阻搭接而进行的测量方法。     

TC_4钛合金超塑成形/扩散连接组合工艺应用研究

 TC4（Ti-6Al-4V）钛合金板材超塑成形/扩散连接（SPF/DB）组合工艺的可行性和对影响钛板SPF、SPF/DB的主要工艺因素。着重阐述某机框段和舱门的研制情况,提供了合理的工艺参数和流程。     

DD3单晶合金瞬间过渡液相扩散焊接头组织与性能

采用粉状中间层合金D1P和非晶态箔状中间层合金D1F对镍基单晶高温合金DD3进行了TLP扩散焊,并对接头组织与性能进行了分析研究。试验结果表明,D1P粉状中间层合金TLP扩散焊接头中存在明显的组织不均匀现象,经过高温长时间保温才可消除,而采用D1F非晶态箔状中间层合金TLP扩散焊DD3合金更易获得与母材组织一致的接头。在合适的规范下,两种中间层合金扩散焊的DD3合金接头980℃持久强度均达到或超过母材的90%。     

Al合金与复合材料LID连接接头微观结构分析

通过SiC颗粒增强Al基复合材料与Al合金的液相界面扩散 (LID)连接试验 ,重点研究了连接接头区域的微观组织 ,并简要分析了接头中各元素的浓度分布情况。结果表明 ,LID连接Al基复合材料和Al合金形成的界面明显向Al合金一侧偏移 ,并且溶质原子在界面两侧分布存在明显的不对称现象。研究结果为异种材料的连接提供了重要的科学依据     

间隙连接对胶接接头应力分布和强度的影响

运用弹塑性有限元法结合实验研究了连续和间隙连接的单搭接接头应力分布规律，并考虑了胶瘤的影响。结果表明，在相当大间隙长度范围内和适当的间隙位置条件下，间隙连接接头并没有大幅度地减小其承载能力，相反其有效搭接区域剪切强度呈明显升高趋势；胶层应力峰值仍然发生在搭接末端；胶瘤承担了相当大的载荷作用；过大的间隙长度以及不当的间隙位置会导致胶层靠近间隙端应力集中明显加剧，成为新的高应力区，可能导致接头破坏模式的改变。实验结果与数值分析结果很好地吻合。     

Fabrication of Ti/Al/Mg laminated composites by hot roll bonding and their microstructures and mechanical properties

Ti/Al/Mg laminated composites were successfully fabricated by hot roll bonding. The effects of the rolling reduction on the microstructural evolution and mechanical properties of the composites were explored. The results show that Ti/Al/Mg laminated sheets exhibit good interfacial bonding. The rolling reduction has a significant effect on the deformation inhomogeneity through the thickness of the Al layer. The initial grains of the Al layer near the Ti/Al interface are fragmented into fine equiaxed grains, and the grains at the center and near the Al/Mg interface are elongated. The R-cube shear texture of the Al layer forms near the Ti/Al interface and permeates into the center layer in the samples with greater rolling reductions. The β-fiber rolling texture of the Al layer is observed near the Al/Mg interface and increases with the increase of rolling reduction. The stress–strain curves indicate that the fracture appears first in the Mg layer. With the increasing rolling reduction, the ultimate tensile and yield strength values increase, and the elongation up to the Mg layer fracture decreases.     

弱界面黏结通用单胞模型数值分析

为考查通用单胞模型和弱界面分离模型模拟复合材料界面脱黏的有效性,考虑了柔性界面,常响应界面和渐进适应界面三种不同的界面分离模型,并分析了界面对材料性能的影响.计算结果表明,将界面分离模型集成到通用单胞模型中,增强了通用单胞模型的适用范围和对复合材料力学响应特性的模拟分析能力.      

复材制件粘接用J-116胶膜工艺性研究

航空产品中的加筋壁板、蜂窝夹层结构件等主承力、次承力构件多采用复合材料胶接技术。环境湿度是造成质量波动主要原因之一,环境湿度会使材料在胶接过程中发生吸湿,当湿度过高时,胶接面水分的存在,可能会对胶接质量产生不良影响。模拟不同湿度条件下,J-116B环氧胶膜粘接QY9511体系复合材料加筋壁板时,胶接面呈现的不同状态,验证了不同环境湿度条件下胶膜的工艺性。结果表明,环境湿度过高,会对最终 的粘接质量造成不良影响,导致明显缺陷。     

Microstructural formation and mechanical performance of friction stir double-riveting welded Al-Cu joints

A novel friction stir double-riveting welding (FSDRW) technology was proposed in order to realize the high-quality joining of upper aluminum (Al) and lower copper (Cu) plates, and this technology employed a Cu column as a rivet and a specially designed welding tool with a large concave-angle shoulder. The formations, interfacial characteristics, mechanical properties and fracture features of Al/Cu FSDRW joints under different rotational velocities and dwell times were investigated. The results showed that the well-formed FSDRW joint was successfully obtained. The cylindrical Cu column was transformed into a double riveting heads structure with a Cu anchor at the top and an Al anchor at the bottom, thereby providing an excellent mechanical interlocking. The defect-free Cu/Cu interface was formed at the lap interface due to the sufficient metallurgical bonding between the Cu column and the Cu plate, thereby effectively inhibiting the propagation of crack from the intermetallic compound layer at the lap interface between the Al and Cu plates. The tensile shear load of joint was increased first and then decreased when the rotational velocity and dwell time of welding tool increased, and the maximum value was 5.52 kN. The FSDRW joint presented a mixed mode of ductile and brittle fractures.