轧制变形量对AA7085铝合金组织和性能的影响

本文采用不同变形量对均匀化后的AA7085铝合金进行轧制,并对所得样品进行单级固溶和峰值时效热处理,通过金相、显微硬度测试研究预变形处理带来的变形强化效果。结果显示:随着AA7085铝合金预变形量的增大其经过固溶时效热处理后的强度提高,在较大变形量条件下,增大预变形量所导致的变形组织强化效果减弱。     

双级时效制度对7150铝合金微观组织和性能的影响

采用拉伸测试、电导率测试和透射电镜等手段研究了双级时效制度对7150铝合金的力学性能、电导率和微观组织的影响。结果表明:在本研究范围内,第一级时效制度对合金的力学性能和电导率影响不大;合金经过120℃/8h+160℃/6h,可以达到与单级峰时效处理相当的抗拉强度,并且电导率有明显提高;第二级时效温度为168℃时效时,相比在160℃进行第二级时效,合金在具有同等电导率水平时,损失的强度相对较多,但时效时间明显变短;120℃/8h+160℃/32h双级时效后,合金的抗拉强度为560MPa,屈服强度为520MPa,延伸率为11.5%,电导率22.7MS.m-1,晶内沉淀析出相以η′和η为主,晶界析出相完全断开。     

焊后时效对6061-T6铝合金搅拌摩擦焊接头的影响

对4组6061-T6铝合金搅拌摩擦焊接头进行焊后人工时效处理,采用OM,SEM等分析了时效处理工艺对接头的组织和力学性能的影响规律和机制。研究表明:焊缝截面形貌呈现典型的3个区,时效处理后,焊缝区晶粒形貌无显著变化,晶界较自然时效清晰,晶内析出相也明显增多;接头强度和显微硬度随人工时效处理时间的延长而提高,提高幅度随保温时间逐渐减小;时效处理为8 h时接头力学性能优良,接头抗拉强度均达到265 MPa以上,约为母材的93.0%;焊核区硬度达到90 HV,约为母材的90%。时效处理中,焊接过程中固溶在基体中的第二相粒子析出,形成弥散强化效应,大幅提高接头的强度和硬度。随着时效时间的延长,析出粒子逐渐较少,强化效应逐渐减弱;接头最薄弱的区均位于后退侧的热机械影响区,其最低硬度值约为母材的75%。拉伸断口均与拉伸方向成约45°角,断口平整,呈典型的切断断口形貌,与自然时效接头的断口形貌相比,时效处理后接头的断口韧窝大而浅,塑性稍有降低。     

Prestrain and Aging Treatment to Improve the Mechanical Properties of AA6022 Aluminum Alloy Laser Weldment

This study aimed to improve the mechanical properties of aluminum alloy sheet laser weldments. Different tensile prestrains, which simulate sheet forming, were applied to a base metal and its Nd:YAG laser weldment, respectively; then, some samples were subjected to a paint-bake-cycling (PBC) process and some samples were subjected to an artificial aging treatment of 175 °C/1000 min. The tensile test and Vickers hardness test, followed by transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), and electron-probe microanalysis (EPMA), were applied to examine the microstructures and compositions. The results showed that tensile prestrain and heat-treatment conditions affect the mechanical properties in relation to the different strengthening mechanisms involved. Compared to traditional PBC processes of auto-body panel production, a weldment applied with an artificial aging treatment at 175 °C/1000 min could significantly improve the yield strength and hardness through its precipitation strengthening mechanism. This operation process also reduces the property mismatch between the base metal and weldment. Although the elongation ratio of the weldment is typically inferior to the base metal, the sheet forming process (as prestrain) can be operated on the weldment successfully, while leaving some elongation capability for auto-body panel. Therefore, the proposed aging treatment for the weldment provided in this article is a promising technique.     

双级时效对7075铝合金力学性能的影响

本文研究了7075铝合金固溶处理后双级时效热处理工艺,分析了双级时效工艺对7075铝合金力学性能的影响.合金成份一定的7075铝合金挤压型材,经470℃2h固溶后,再经120℃×6h+165℃x5h双级时效时能获得较好的综合性能,为7075铝合金时效热处理工艺参数的确定及优化提供参考依据.     

化学成分对6082铝合金晶间腐蚀的影响

研究化学成分对6082铝合金晶间腐蚀的影响。结果表明合理控制Mg、Si及Cu元素的含量,能够很好的控制合金的晶间腐蚀。     

高性能瓶盖用热轧AA8011-H16铝合金带材的生产工艺研究

从瓶盖用铝合金带材的质量要求入手,采用正交试验法通过五种试验工艺对瓶盖料的生产工艺进行了分析研究,从而得出了生产高性能瓶盖AA8011-H16铝合金带材的生产工艺。     

Effect of Alloy Composition on the Dendrite Arm Spacing of Multicomponent Aluminum Alloys

Predictions of secondary dendrite arm spacing (SDAS) for multicomponent aluminum alloys using a dendrite ripening model are compared with experimental observations. For six of the seven alloys studied, the predicted SDAS was within 20 pct of the measured SDAS. It was found that the final SDAS was dependent upon both the solidification time and the solute profile of the solidifying alloys. It is interesting that while the solidification times and the solute segregation during solidification varied significantly over the range of alloys, these two factors largely canceled each other out so that the predicted SDAS did not vary much between the alloys. The experimental and modeling results show that elements causing high constitutional undercooling near the beginning of solidification, e.g., Ti, which reduces the grain size substantially, have little effect on the SDAS. Instead, it was found that elements that strongly partitioned toward the end of solidification were more effective at restricting SDAS coarsening.     

时效工艺对7A09铝合金板材组织及性能的影响

从7A09铝合金60mm厚度的淬火拉伸后板材切取试料,在箱式时效炉进行不同时效制度处理,从而研究时效制度对7A09铝合金板材性能和组织的影响,确定了60mm厚7A09铝合金板材的合理时效工艺制度,为实际生产该合金板材提供了一定的依据和技术支持.     

时效处理对7A04铝合金晶问腐蚀性能的影响

基于7A04铝合金热处理强化机制,拟从深冷并多种时效方面改进工艺,以改善7A04铝合金沉淀析出的均匀性,从而减小7A04铝合金晶间腐蚀倾向.实验设计不同时效工艺,进行7A04铝合金不同工艺的处理,对处理后材料的组织和晶间腐蚀性能进行测试,研究7A04铝合金组织对晶间腐蚀性能的影响.结果表明:时效温度为130℃,采用水淬+深冷这一冷却方式的试样获得的抗晶间腐蚀性能更好.     

时效热处理对6082-T6铝合金型材力学性能的影响

试验研究了淬火后停放时间及时效工艺对6082-T6铝合金型材力学性能的影响,结果表明,在综合考虑工业化实际生产条件下建议采用26h~30h的淬火后停放时间;6082-T6铝合金型材无淬火停放时最佳时效工艺为175℃×4h。     

Effect of Scandium on the Interaction of Concurrent Precipitation and Recrystallization in Commercial AA3003 Aluminum Alloy

In the current study, the effect of Sc addition on the interaction of concurrent precipitation and recrystallization in commercial AA3003 aluminum alloy was investigated using optical microscopy, scanning electron microscopy, and transmission electron microscopy. In case of AA3003 alloy, which was cold rolled to a true strain of 2.20 and heated at a heating rate of 150 K/s, the onset of precipitation and ending of recrystallization are signified by the critical temperature, T _C ~740 K (467 °C). There is a change in the shape of the recrystallized grains from pancake-like to equiaxed shape, as the annealing temperature increases greater than T _C. In case of AA3003 alloy microalloyed with 0.4 wt pct of Sc, the high no. density precipitation of coherent Al₃Sc precipitates always occurs before recrystallization because of the small nucleation barrier and high rate of decomposition. This leads to extremely coarse pancake-like recrystallization grains with high fraction of low-angle grain boundaries in the entire annealing temperature range, even at a high brazing temperature of 883 K (610 °C).     

合金成分与组织结构对铝合金阳极氧化的影响

本文叙述合金化元素、杂质元素及显微结构对铝合金阳极氧化的影响，介绍熔铸、热处理、加工成型及化学预处理等工艺参数对阳极氧化的作用。     

The Effect of Iron Content on the Iron-Containing Intermetallic Phases in a Cast 6060 Aluminum Alloy

The effect of iron content, ranging from 0.1 to 0.5 wt pct, on the formation of Fe-containing intermetallic phases in a cast 6060 aluminum alloy was investigated. Various characterization techniques, including optical microscopy, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM) were used to examine the identity, morphology, and prevalence of the Fe-Al and Fe-Al-Si intermetallic phases. The predominant phase is found to be β-Al₅FeSi at lower Fe levels, but this is replaced by α-AlFeSi (bcc structure) with increasing Fe content. The Fe containing intermetallic phases observed are compared to those predicted using the Scheil module of THERMO-CALC software, and the similarities and discrepancies are discussed.     

Effect of Operation Parameters on Diffusion Bonded AA5083, AA6082 and AA7075 Aluminum Alloys

Rolled plates of 5 mm thick AA5083, AA6082 and AA7075 aluminum alloys Joints were fabricated by diffusion bonding at different temperatures. The microstructure evolution of AA5083, AA6082 and AA7075 aluminium alloys were characterized by transmission electron microscopy. Metallurgical investigations and mechanical tests were also performed to correlate the microstructural investigations with the mechanical properties of the produced diffusion bonded joints. It was observed that the bonding and shear strength increased with the increase in bonding temperature due to the diffusion of micro-constituents in the interface. Higher temperature enhanced the uniform distribution of secondary phase particles, which further improved the reduction in pores/defects in the bonded joints.     

不同结晶相的三(8-羟基喹啉)铝的研究进展

综述了三(8-羟基喹啉)铝(Alq3)的5种结晶相(α,β,γ,δ和ε)的制备方法以及这五相之间的相互转变。阐述了Alq3的两种异构体(fac-Alq3和mer-Alq3)的相互转变和存在条件,研究表明:由于室温下fac-Alq3在溶液中很不稳定,所以很难被检测到,其只能在低温下存在,并随着温度的升高逐渐向mer-Alq3转变。归纳了Alq3的5种结晶相的不同结晶形式和晶体结构。并对比了这5种结晶相在固态和溶液中的光致发光光谱,发现不同结晶相的荧光峰值波长不同,并分布在466～515 nm之间。最后简述了Alq3合成过程中的化学老化机制:在水和氧气存在的情况下,Alq3易水解进而发生氧化缩合,因此在制备Alq3的过程中需要在无水无氧的条件下进行。     

不同热处理工艺对4A11铝合金锻件时效性能的影响

研究4A11合金热处理强化的可行性,在试验及生产的基础上,重点研究不同时效工艺4A11合金组织和性能变化,总结出不同产品标准的热处理工艺方案,并应用到生产中,取得较好效果。     

Influence of Radial-Shear Rolling Conditions on the Metal Consumption Rate and Properties of D16 Aluminum Alloy Rods

Metallurgist - The effect of five cases of temperature-and-speed conditions in radial-shear rolling (RSR) of D16 alloy is analyzed. The temperature of the rod after each pass is obtained from the...     

Al-Ti-B晶粒细化剂微观组织对AA1050合金细化效果的影响

分析了两种Al-Ti-B晶粒细化剂的成分及微观组织,并在同等试验工艺、相同细化剂添加量的条件下,比较了两种Al-Ti-B丝晶粒细化剂对AA1050合金的细化效果.