Corrosion-induced hydrogen embrittlement in aluminum alloy 2024

The present paper focuses on the observed corrosion-induced embrittlement of alloy 2024 and tries to answer the key question on whether the observed embrittlement is attributed to hydrogen uptake and trapping in the material. Hydrogen is produced during the corrosion process and is being trapped in distinct energy states, which correspond to different microstructural sites. The formation of a hydrogen-affected zone beneath the corrosion layer is supported by fractographic analysis. Removal of the corrosion layer leads to complete restoration of yield strength but only partial restoration of ductility. Additional heat treatment to release the trapped hydrogen leads only to complete restoration of ductility.     

Structural strength of aluminum alloy plates for a new generation of aircraft

Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 23–25, December, 1991.     

A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy

Hydrogen partial pressure is an important parameter to calculate hydrogen concentration levels in molten aluminum alloy. A new dynamic method for measuring hydrogen partial pressure in molten aluminum alloy is studied. Dynamic and rapid measurement is realized through changing the volume of the vacuum chamber and calculating the pressure difference ΔP between the theoretical and measured pressures in the vacuum chamber. Positive ΔP indicates hydrogen transmits from melt to vacuum chamber and negative ΔP means the reverse. When ΔP is equal to zero, hydrogen transmitted from both sides reached a state of dynamical equilibrium and the pressure in the vacuum chamber is equal to the hydrogen partial pressure in the molten aluminum alloy. Compared with other existing measuring methods, the new method can significantly shorten the testing time and reduce measuring cost.     

铝合金型材在线水冷淬火设备

简介铝合金在线水冷淬火设备的结构组成,以及6061铝合金挤压型材在线水冷淬火试验情况,型材经水冷淬火后再经人工时效处理,其力学性能满足标准规定值.该设备投资少,运行稳定,维护方便,有较好的经济和技术效益.     

铝合金模锻件折叠缺陷产生的原因与预防措施

“折叠”是铝合金模锻件的常见缺陷。从生产实际出发 ,对模锻件折叠缺陷产生的原因进行了细致分析 ,模具设计不合理、坯料选择不当、压下量过大、润滑不均匀及上道工序修伤不彻底 ,均可导致折叠缺陷。提出了预防折叠缺陷的具体措施。     

船用5052-O铝合金在海水中的力学和电化学性能(英文)

采用电化学实验和SEM表面形貌观察,对船用5052-O铝合金在海水中的腐蚀保护电位进行优化,以克服诸如点蚀、腐蚀、应力腐蚀开裂和氢脆等行为的发生。在外加电流阴极保护的条件下,最优的保护电位范围为-1.3V～-0.7V。在此电位下,试样的腐蚀电流密度较低,经恒电位实验后,试样表面形貌保持得较好。     

铝合金加工过程中含铬废水的处理

在铝合金加工过程中产生的含铬废水中六价铬离子对人体危害很大,铁氧体法处理六价铬离子是一种无中间二次污染物,能达到一步无害化处理,处理后的废水达到了国家规定的排放标准,有显著的经济效益和环境效益。     

铝合金精密挤压技术

介绍铝合金精密挤压的特点和技术要求,以及一些小型精密铝合金型材实例。     

The effect of hydrogen charging on the mechanical behaviour of 5083 wrought aluminum alloy

The effect of hydrogen cathodic charging on the mechanical behaviour of 5083 wrought aluminum alloy has been studied. Hardening of the surface layers of the examined alloy, due to hydrogen absorption, was observed. The tensile tests revealed that the ductility of 5083 wrought aluminum alloy decreased with increasing hydrogen charging time, for a constant value of charging current density, and with increasing charging current density, for a constant value of charging time. However, the ultimate tensile strength of the examined alloy was slightly affected by the hydrogen charging procedure. The cathodically charged 5083 wrought aluminum alloy exhibited brittle transgranular fracture at the surface layers and ductile intergranular fracture at the deeper layers of the alloy.     

铝合金激光焊接技术研究进展

综述铝合金激光焊接技术特点及研究现状,开展3 mm厚LF6铝合金激光-MIG电弧复合焊接工艺研究。文献综述表明,铝合金激光自熔焊接表面成形不好,且易于产生气孔缺陷,激光填丝焊、激光-电弧复合焊以及双光束激光焊等能够有效地解决上述铝合金激光焊接问题。试验研究表明,激光-MIG电弧复合焊接LF6铝合金可获得良好的焊缝成形,内部质量达到QJ1666A-2011Ⅰ级焊缝质量要求,接头强度达到母材的90%以上,具备较为优异的力学性能。     

铝合金旋压的研究动态

旋压加工技术是借助旋轮、芯模等工具旋转,使金属产生连续的局部塑性变形而加工成空心回转体零件的工艺.综述了铝合金的旋压工艺特点、影响因素、数值模拟等方面的研究现状,提出了今后的发展方向.     

铝合金连续铸造喷水冷却的换热系数

基于边界条件替换法建立了铝合金连续铸造喷水冷却过程的换热系数计算模型.采用实验测量铸锭冷却过程的表面温度和温度场数值计算相结合的方法,确定了铸锭表面温度为100～500 ℃和喷水密度为11.3～27.8     

铝合金薄壁管旋压封口工艺

铝合金薄壁管可以作为刚性取样管,应用在航空、航天和地质探测等研究领域。为保证样品的科学研究价值,需要对铝合金薄壁管两端封口以隔绝与外界的环境。文章采用旋压工艺对装满样品的铝合金薄壁管两端封口成形工艺进行实验研究。结果表明,通过控制旋压封口工艺的主要技术参数,可以使铝合金薄壁管获得良好的两端封口效果。研究获得了旋压力与旋轮进给率、旋压力与旋轮形状、壁厚减薄率与旋轮进给率的关系。     

铝合金的淬透性及其研究方法

简介钢材的淬透性,以便于我们研究铝合金淬透性时拓宽思路.对铝合金材料的淬透性及其研究成果和研究方法进行了论述.     

关于铝及铝合金的焊接工艺浅析

随着铝及其合金越来越多的被用于化工、航空航天、汽车制造等工业生产中,焊接结构不可避免,为了更好的解决铝、尤其铝合金的焊接工艺问题,我们通过实践,总结出一些系统的、比较成熟的工艺路线。并从理论上作了具体的论证,从而较好的解决了焊接铝合金的难点。     

铝材纳米成形技术与应用

介绍了铝塑结合工艺常用方法和纳米成形技术的发展,叙述了铝合金零件纳米注射成型工艺的主要影响因素,展望了纳米成形技术的应用前景。