在线淬火强度对6×××系铝合金型材腐蚀性能的影响

针对工业化生产的6061、6005A、6082、6063和6N01合金型材,在不同淬火方式下进行腐蚀试验,了解各合金的腐蚀级别,并对工业生产提供一定的指导。6061和6005A合金型材因含Cu存在剥落腐蚀和晶间腐蚀现象,6063、6082和6N01合金型材在不同淬火条件下均呈现出较好的腐蚀性能。

6×××系铝合金微合金化的研究进展

6×××系(Al-Mg-Si)铝合金作为综合性能良好的中强铝合金,在航天工业和民用等领域具有广阔的应用前景,微合金化是提高铝合金性能的有效途径,也是研制新型铝合金的重要手段,是国内外铝合金研究的热点之一。综述了6×××系铝合金中元素Mg、Si、Cu、Mn、Sr、Zr、Sc等的作用,探讨了该系铝合金目前存在的问题和发展方向,指出了寻求廉价且有效的微合金化元素、进一步探明微合金化作用机理和复合微合金化是今后研究的主要方向。

热轧板退火温度对6×××系铝合金β″相析出动力学的影响

采用差示扫描量热法(DSC)研究热轧板退火温度对6×××系铝合金时效过程中β″相析出动力学的影响。计算热轧板在不同退火温度下β″相形成激活能,并对不同热轧板退火温度的试样模拟烤漆后进行力学性能实验。结果表明:随着热轧板退火温度的提高,β″相的形成激活能略微降低,表明在时效过程中β″相更容易形成,合金的模拟烤漆强度因此得到提高。热轧板退火温度的提高,增大了基体中的Mg、Si原子的过饱和度,即增大了时效过程中β″相的形成驱动力,从而提高合金的模拟烤漆强度。

6×××系铝合金的晶间腐蚀评价方法研究

采用腐蚀深度法和质量损失法分别对6×××系铝合金的晶间腐蚀敏感性进行评价,并借助金相显微镜和扫描电镜对晶间腐蚀形貌和腐蚀产物进行观察和分析,从而选择适宜的晶间腐蚀评价方法。结果表明:6×××系铝合金具有一定的晶间腐蚀敏感性,其评价方法宜选择腐蚀深度法,腐蚀溶液为57gNaCl+10mLH_(2)O_(2)/1000m L H_(2)O,腐蚀温度为30℃,时间为24h。

高性能超流6×××系铝合金的进展

对6 x x x系铝合金的进展作了简要概述。6 xxx系铝合金属Al-Mg-Si系,组织比较简单,主要强化相为Mg2Si。2018年在美国铝业协会公司注册的706个变形铝合金中,6 x xx系铝合金126个,占17.85%,居第二位。但是6 xxx系铝合金半成品产量却居首位,据匡算,约占铝材总产量的30%以上。对加拿大铝业公司/力拓公司研发的高性能6360、高性能超流6063、高性能超流6060铝合金作了较多的叙述,介绍了其成分设计思路、生产工艺参数、性能与用途等。

汽车用6×××系铝合金及其冲压成形性研究综述

铝合金具有比强度大、成形性好、导热性好、耐腐蚀及性价比高等优点,能够满足汽车轻量化的需求。对6×××系铝合金板材的研究现状作了综述,主要内容包括6×××系铝合金的合金元素、织构、力学性能和冲压成形性。6×××系铝合金板材与钢板相比,其成形性、刚度和抗凹陷性都较低,为使合金板材更好地满足汽车轻量化的需求,应综合考虑合金元素、织构、热处理状态和成形工艺等方面对成形性能的影响,优化合金板材的冲压成形性,研制出综合性能更优的车身板材,以提高汽车车身用铝量。

高强耐热6×××系铝合金的研究现状及其发展趋势

6×××系铝合金由于其密度低、易成形、耐蚀性好等优点,广泛应用于汽车及建筑领域。随着对6×××系铝合金使用要求的不断提高,人们对该系铝合金的强度及耐热性提出了更高的要求。介绍了微合金元素Mn、Cr、Fe、Zr、Sc等对6×××系铝合金组织及性能的影响,复合微合金化及Al_(3)(Sc,Zr)等复合粒子对提高6 xxx系铝合金力学性能的作用。综述了传统的轧制工艺及新型轧制变形工艺对6×××系铝合金组织及性能的影响,国内外对6×××系铝合金耐热性的研究现状,对6×××系铝合金的热处理强化手段进行概述,并对高强耐热6×××系铝合金的发展趋势进行展望。

6×××系铝合金薄板预时效工艺探索

通过分析国内外有关6×××系铝合金薄板预时效工艺优劣特点,制定了适合我公司的预时效工艺方案。实验结果表明:6×××系铝合金薄板在560℃、120s固溶淬火后进行短时预时效可以达到预期的性能,通过一定程度的提高预时效温度或延长保温时间,合金板材的烤漆硬化性能得到增强,但过高的预时效温度不利于板材的冲压性能,最佳预时效工艺为150℃/1min。

6×××系铝合金汽车防撞梁高速碰撞分析

以某车型前防撞梁为研究对象,利用仿真软件对其在高速正面碰撞下的工况进行模拟,从仿真结果中对模型的能量变化及质量变化得出模型建立的正确性与可靠性。通过分析部件的吸能、变形特性及截面力时间历程曲线,得出该防撞梁系统可达到汽车零部件设计中轻量化、安全性标准,对今后铝制防撞梁的结构设计具有一定的参考价值。

电解原铝液DC铸造6×××系铝合金铸锭的枝晶组织

采用金相分析方法研究了电解原铝液直接合金化、DC铸造6063、6N01及6061铝合金Φ200 mm铸锭的显微组织尤其是枝晶分布规律。结果表明:3种合金铸态组织均呈明显的树枝晶状,存在严重的枝晶偏析,其枝晶直径及枝晶臂间距从铸锭心部向铸锭表面逐渐细化;3种合金铸锭的枝晶臂间距及枝晶直径随合金铸锭中合金元素含量增加呈现出逐渐粗化的趋势,即合金元素总质量分数最低为1.141%的6063铝合金铸锭枝晶直径及枝晶臂间距最细小,而合金元素总质量分数最高为2.05%的6061铝合金铸锭枝晶直径及枝晶臂间距最大。

6×××系挤压型材力学性能的季节性变化

采用数据统计、布氏硬度测试、室温拉伸力学性能、扫描电镜等方法研究了6×××系挤压型材力学性能的季节性变化行为。结果表明,型材的力学性能存在季节性变化,且这种变化是由夏季、冬季不同的自然时效效应引起的。根据实际情况适当调整时效制度可以减小型材力学性能的季节性波动,稳定型材质量。

一种新型6×××系汽车车身板均热加热分离方案的工艺研究

可热处理强化的6×××系铝合金由于其优良的综合力学性能、冲压成形性能以及抗腐蚀性能,是目前汽车轻量化的理想材料,主要用作汽车车身板。本文对一种新型汽车车身用6×××系铝合金均热加热分离工艺进行了可行性研究。研究结果表明:均热加热分离工艺与均热加热一体化工艺制备的板材性能相当。铸锭于550℃下均匀化退火后冷却到200℃的冷却时间至关重要。如果冷却时间短于2 h,均热加热分离工艺可以替代均热加热一体化工艺。

Shp-2／NF-κB Pathway Mediates the Inhibition of Lipoxin A4 onIL-1β-induced Synthesis of IL-6 in Glomerular Mesangial Cells

Objective: To examine whether lipoxin A 4 (LXA 4) has an antagonistic effect on IL-1β-induced synthesis of IL-6 in glomerular mesangial cells, and to explore the molecular mechanisms of signal pathway in LXA 4 actions. Methods: The glomerular mesangial cells of rat were cultured and treated with IL-1β, with or without preincubation with LXA 4 at different concentrations. The amount of IL-6 in the supernatant of cells was analyzed by enzyme-linked immunosorbent assay(ELISA). The expressions of mRNA of IL-6 were determined by RT-PCR. The expressions of Src homology 2(SH 2) containing protein-tyrosine phosphatase 2(Shp-2) were assessed by immunoprecipitation and immunoblotting. Activities of DNA-binding of nuclear factor-kappa B(NF-κB) were measured by electrophoretic mobility shift assay(EMSA). Results: IL-1β-stimulated secretion of protein and expression of mRNA of IL-6 in mesangial cells were inhibited by LXA 4 in a dose-dependent manner. LXA 4 antagonizes the phosphorylation of Shp-2 and activities of NF-κB induced by IL-1β. Conclusion: LXA 4 antagonists IL-1β-induced synthesis of IL-6 in glomerular mesangial cells through the mechanism of Shp-2/NF-κB pathway-dependent signal transduction.

CLINICAL APPLICATION OF NEIGUAN (内关 PC 6) IN THE TREATMENT OF DISORDERS OF THE DIGESTIVE SYSTEM——THE RELATED RESEARCH PROGRESS

In the present paper, the authors review recent situations of clinical application of Neiguan (PC 6内关), etc. in the treatment of disorders of the digestive system and its related research progresses. In clinical practice, Neiguan (PC 6) is usually selected as one of the main acupoints to treat gastrointestinal reactions induced by ① nausea and vomiting, ② hiccup, ③ gastrointestinal dyskinesia, ④ gastritis, and ⑤ intra-gastric examination, cesarean section, etc. Concerning experimental studies, the effects of Neiguan (PC 6), etc. on ① gastric electrical activities, ② gastrointestinal motion, ③ gastrointestinal hormone secretion, and ④ gastric mucosal structure were observed. Results indicated that Neiguan (PC 6) is an important and effective acupoint for treatment of gastrointestinal disorders in clinic. Stimulation of Neiguan (PC 6) induced favorable regulation of both the peripheral nervous system and central nervous system, and changes of the gastrointestinal hormone secretion may contribute to its effects in treating various disorders.

铝桥及桥梁铝材

截至2012年全世界共建造约365座铝桥,大多数在北美、北欧和西欧。95%以上的铝桥为公路桥和人行桥,铁路桥极少。20世纪50年代以前铝桥为板梁结构,60年代以后改为大挤压型材结构。铝桥未得到推广是因为一次性投资高,但一旦建好终身不需要维护,而钢桥每隔若干年需维护一次。若将两种费用捆在一起计算,则铝桥的总造价并不比钢桥的高。至2014年5月中国建成了7座铝合金结构的人行过街天桥,中国不但掌握了桥梁铝材的生产技术,而且掌握了铝桥梁的设计、制造与安装技术。铝桥是环保的、免维护的、可循环发展的,中国应大力发展铝桥,特别是人行过街天桥。铝桥用的铝材多是用6×××系合金挤压的,可焊的7×××系合金是潜在的良好材料。

Acceleration of Immune Reconstitution after Bone Marrow Transplantation in Mice by Bone Marrow Stromal Cell Line Transfected with IL-6 Gene

To observe potential effect of the engineered bone marrow stromal cell line QXMSC1 secreting IL-6 (QXMSCIL-6) on accelerating immune reconstitution in syngeneic bone marrow transplantation in mice, QXMSC1 was transfected with the eukaryocytic expression vector pcDNAIL-6, which contained hIL-6 cDNA by liposome-mediated gene transfecting technique. G418-resistance clone was selected by limiting dilution. The highest secreting clone was selected by ELISA assay and used in animal experiments. The recipient mice (BALB/c) were lethally irradiated and cotransplanted syngeneic bone marrow (10 7/mice) and the QXMSC1IL-6 (5×10 5/mice). Lymphocyte proliferation induced by ConA and LPS, helper T lymphocyte precursor (HTLp), cytotoxic T lymphocyte precursor (CTLp), plaque-forming cell (PFC), delayed type hypersensitivity (DTH) were examined 30, 60 days in post transplantation respectively. The results showed that lymphocytes proliferation to ConA and LPS, HTLp, CTLp increased, DTH and PFC were improved by cografted stromal cells QXMSC1IL-6 on 30, 60 days after BMT. These results demonstrated that the bone marrow stromal cell line QXMSC1IL-6 transfected with IL-6 (QXMSC1IL-6) accelerated immune reconstitution in syngeneic bone marrow transplantation.

Al-1.3Si-0.7Mg-0.7Cu-0.3Mn铝合金薄板在固溶处理过程中的组织转变

通过XRD,OM和TEM组织观察、织构测定等方法研究了冷轧Al-1.3Si-0.7Mg-0.7Cu-0.3Mn铝合金汽车车身板在固溶处理过程中其合金相、晶粒、织构组态的变化.结果表明:Al-1.3Si-0.7Mg-0.7Cu-0.3Mn合金冷轧薄板中存在Al9Fe0.84Mn2.16Si,Al95Fe4Cr和Al6Mn不可溶合金相及Al1.9CuMg4.1Si3.3和Mg2Si可溶合金相;尺寸小于1μm的可溶合金相在540℃盐浴固溶中保温12 min以上即可全部溶入基体;冷轧薄板在540℃固溶保温2 min即可完成再结晶,形成{001}〈310〉和{110}〈113〉再结晶织构,其中以{001}〈310〉组分为主,但两种再结晶织构的强度均偏低.延长固溶保温时间至60 min,晶粒尺寸、形状及织构组态无明显变化.

Electroanalytical studies on electrically conductive polyaniline： Nylon-6,6 composite film

Electrically conductive composite films ofpolyaniline and nylon-6.6 are prepared by diffusing aniline followed by oxidative polymerization of aniline into nylon-6.6 matrix. In order to determine the diffusion coefficient for the chloride ion diffusion into the composite matrix electrochemically, galvanostatic pulse method is used and the diffusion coefficient is estimated to be -6.48× 10^-17 cm^2s^-1. The results are discussed in view of them being potential replacement materials for battery. electrodes and sensors devices.

铝合金在光伏支架上的应用

阐述了铝合金光伏支架的设计、材料选择、结构形式、加工和注意事项,对比了铝合金光伏支架与钢支架在综合成本和环保方面的优越性,以及铝合金光伏支架的应用实例。指出铝合金光伏支架在光伏电站上必将得到更广泛的应用。

Molecular Dynamics Simulations of Self-diffusion Coefficients of Exponential-six Fluids

Self-diffusion coefficients of exponential-six fluids are studied using equilibrium molecular dynamics simulation technique. Mean-square displacements and velocity autocorrelation functions are used to calculate self-diffusion coefficients through Einstein equation and Green-Kubo formula. It has been found that simulation results are in good agreement with experimental data for liquid argon which is taken as exponential-six fluid. The effects of density, temperature and steepness factor for repulsive part of exponential-six potential on self-diffusion coefficients are also investigated. The simulation results indicate that the self-diffusion coefficient of exponential-six fluid increases as temperature increases and density decreases. In addition, the larger self-diffusion coefficients are obtained as the steepness factor increases at the same temperature and density condition.