Thomas Firth and Sons – Steelmakers to the Arms Industries. Part 2: Heavy Armaments

Firth’s were the first of the Sheffield steel makers to enter the field armaments. Their involvement with Colt has been outlined in an article in the journal of the Colt Collectors Association in America and their activities as steelmakers to the small-arms industries has been covered in a previous issue of this Journal. This article gives a brief overview of their involvement as manufacturers in the field of heavy armaments, being the first to make all-steel guns and their evolving role in the use of steel for ordnance, culminating in the displacement of wrought iron by the adoption of steel for ordnance manufacture by the Royal Gun Factory in the 1880s. It also highlights their development of stainless steel in this context.     

有机羧酸在中性腐蚀介质中对铸铝的缓蚀性能研究

通过电化学方法研究了不同浓度的有机羧酸对偶接及非偶接状态下铸铝的缓蚀性能,并对其缓蚀机理作了初步探讨.结果表明:常温状态下,该有机羧酸对铸铝有着很好的缓蚀效果,且随着其浓度的提高,缓蚀效果增加.此缓蚀剂对铸铝主要表现为几何覆盖效应,为抑制阳极型缓蚀剂.     

两栖车辆用牺牲阳极材料研究进展

结合两栖车辆的发展和两栖车辆牺牲阳极阴极保护性能指标要求,介绍了两栖车辆用牺牲阳极材料研究进展,分析了主要合金元素作用机理。根据牺牲阳极耐干湿交替性能要求和实车试验结果,采用极化时间、车体保护电位、活化性能等技术指标,评价了五元和六元牺牲阳极对两栖车辆阴极保护效果。展望了两栖车辆牺牲阳极阴极保护研究的下一步工作方向和重点。     

基于RUP的航空兵作战C4ISR体系结构研究

本文分析了C4ISR系统的建模特点,对当前主流体系结构模型开发方法进行了比较,提出了运用Rational统一过程（RUP）开发DoDAF体系结构视图产品,并分析了其可行性。结合航空兵作战的特点,采用Rational ROSE建模工具开发了的相关视图产品,描述了航空兵作战过程,证明了RUP对体系结构的开发有着良好的支持作用。     

基于故障树分析的航空装备体系结构贡献率评估方法

针对航空装备体系构成复杂的特点,将故障树分析引入航空装备体系结构贡献率评估问题,提出基于故障树分析的评估方法。从作战装备、信息支援装备和保障装备三个方面构建航空装备体系结构,建造航空装备体系结构故障树;采用底事件的关键重要度指标来计算航空装备的体系结构贡献率,建立基于关键重要度的航空装备体系结构贡献率评估模型;以某航空装备体系为例进行建模分析。分析结果表明:所提方法能够准确评估航空装备体系结构贡献率,为确定航空装备体系结构短板、优化航空装备体系结构等提供方法支撑。     

Effects of nano-sized aluminum on detonation characteristics and metal acceleration for RDX-based aluminized explosive

Nano-sized aluminum(Nano-Al)powders hold promise in enhancing the total energy of explosives and the metal acceleration ability at the same time.However,the near-detonation zone effects of reaction between Nano-Al with detonation products remain unclear.In this study,the overall reaction process of 170 nm Al with RDX explosive and its effect on detonation characteristics,detonation reaction zone,and the metal acceleration ability were comprehensively investigated through a variety of experiments such as the detonation velocity test,detonation pressure test,explosive/window interface velocity test and confined plate push test using high-resolution laser interferometry.Lithium fluoride(LiF),which has an inert behavior during the explosion,was used as a control to compare the contribution of the reaction of aluminum.A thermochemical approach that took into account the reactivity of aluminum and ensuing detonation products was adopted to calculate the additional energy release by afterburn.Combining the numerical simulations based on the calculated afterburn energy and experimental results,the param-eters in the detonation equation of state describing the Nano-Al reaction characteristics were calibrated.This study found that when the 170 nm Al content is from 0％to 15％,every 5％increase of aluminum resulted in about a 1.3％decrease in detonation velocity.Manganin pressure gauge measurement showed no significant enhancement in detonation pressure.The detonation reaction time and reaction zone length of RDX/Al/wax/80/15/5 explosive is 64 ns and 0.47 mm,which is respectively 14％and 8％higher than that of RDX/wax/95/5 explosive(57 ns and 0.39 mm).Explosive/window interface velocity curves show that 170 nm Al mainly reacted with the RDX detonation products after the detonation front.For the recording time of about 10 μs throughout the plate push test duration,the maximum plate velocity and plate acceleration time accelerated by RDX/Al/wax/80/15/5 explosive is 12％and 2.9 μs higher than that of RDX/LiF/wax/80/15/5,respectively,indicating that the aluminum reaction energy significantly increased the metal acceleration time and ability of the explosive.Numerical simulations with JWLM explosive equation of state show that when the detonation products expanded to 2 times the initial volume,over 80％of the aluminum had reacted,implying very high reactivity.These results are significant in attaining a clear understanding of the reaction mechanism of Nano-Al in the development of aluminized explosives.     

航空燃料冰点快速测定方法

冰点是表征航空燃料低温使用性能的重要指标。常规冰点测定方法操作步骤复杂,测定时间长,影响航空燃料质量检测效率。基于光散射原理,将温度传感和光电检测技术应用于航空燃料冰点测定,利用燃料结晶对光散射和透射的影响,实现航空燃料冰点快速测定。该方法操作简单快速,检测1个油样用时少于15 min,大幅提高了冰点检测效率;试样体积仅需2 mL,有利于试验环境保护;测定结果重复性好,与标准方法 GB/T2430—2008具有良好的相关性。     

2A12铝合金焊接接头超声冲击处理前后拉伸性能分析

为克服铝合金薄板焊接接头强度偏低、韧性不足的缺点,用ER5356焊丝对不同厚度的2A12铝合金板材进行了手工氩弧焊接,并采用超声冲击处理对焊接接头进行全覆盖强化处理。采用金相显微镜观察了处理和未处理焊接接头的显微组织结构,对接头的力学性能进行了测试分析,分析了超声冲击处理改善2A12铝合金焊接接头力学性能的机理。结果表明：铝合金焊接接头经超声冲击强化处理后,6 mm和4 mm厚板材对接接头的抗拉强度分别提高了17.4%和23.7%,延伸率分别提高了28%和44%,焊缝表层组织得到明显细化。分析认为：晶粒大幅细化、组织致密化和缺陷减少,是超声冲击处理改善铝合金焊接接头抗拉伸性能的主要原因。     

基于作业成本原理的飞行训练保障费用模型

飞行训练保障费用是飞机使用保障费用中的重要组成部分,也是使用保障费用估算的重点和难点。结合目前航空兵部队实际工作情况,首先利用作业成本法的基本原理,对航空兵部队飞行保障阶段的作业进行划分,得出成本库及成本动因。其次针对军机飞行保障阶段的多种作业,建立基于作业成本法的飞行训练保障费用模型。最后通过算例说明其比其他估算方法所具备的优势。     

储氢电极合金的温度特性研究

针对目前储氢电极合金不适用于电动汽车用大型电池的情况 ,以Ml (NiCoMnTi) 5 合金为例 ,系统研究了温度对储氢电极合金电化学性能的影响。结果表明 :随着温度升高 ,合金的放电容量降低 ,循环稳定性恶化 ,自放电加剧 ;但是在高温下合金的高倍率放电特性得到显著改善。