Corrosion resistance of cerium conversion film electrodeposited on Mg-Gd-Y-Zr magnesium alloy

The cerium conversion film was applied to improving the corrosion resistance of Mg-Gd-Y-Zr magnesium alloy. The film was electrodeposited on the surface of the Mg-RE alloy in cerium nitrate solution. The compositions and morphologies were analyzed by X-ray diffraction(XRD), scanning election microscopy (SEM). The corrosion behaviors of the film were investigated electrochemical impedance spectroscopy (EIS), potentiodynamic polarization tests and immersion tests. The results show that the optimum parameters for electrochemical deposition are as follows: pH 10.0, time 30 min, 50 mmol/L Na₂CO₃ and temperature 25 °C by the designed experiments according to the orthogonal table L(9, 3⁴). The corrosion protection efficiency is dependent on the deposition parameters. The cerium conversion film shows better corrosion protection behavior than chromate conversion film on Mg-Gd-Y-Zr magnesium alloy. Foundation item: Project (5133001E) supported by the Major State Basic Research and Development Program of China     

痕量Ga及退火工艺对高压阳极铝箔电化学性能的影响

通过开路电位—时间曲线、极化曲线和恒电位电流密度暂态曲线研究痕量Ga及退火工艺对高压阳极铝箔电化学性能的影响,在此基础上,结合光学显微镜和扫描电镜研究痕量Ga对阳极铝箔腐蚀发孔性能的影响。结果表明,退火工艺可以改变Al-44×10-6 Ga在含氯离子溶液中的电化学活性。提高退火温度(200~600℃)可促使Al-44×10-6 Ga的点蚀电位负移,500℃退火、保温1 h后,延长退火保温时间(4~12 h),点蚀电位变动很小;相对无Ga高纯铝,Ga含量为44×10-6的高纯铝在中性NaCl溶液中的开路电位向负电位方向移动约0.1~0.15 V、点蚀电位负移约0.11 V,并能在更负的电位下发生活性溶解;进而使相应的含Ga铝箔的腐蚀区面积比显著提高至96.5%,且蚀孔密度、分布均匀性提高,即痕量Ga改善了阳极铝箔在环保型盐酸-硫酸体系中的腐蚀发孔性能。     

双辊快速凝固制备颗粒增强铝基复合材料的新途径

为了制备基体晶粒细小、增强颗粒分布均匀且与基体结合良好、界面上无明显反应产物的颗粒增强铝基复合材料，在铝及铝合金双辊快速凝固技术研究的基础上，提出了同步喷射增强颗粒和结合熔体接触反应法的两种双辊快速凝固制备方法，介绍了这两种方法制备颗粒增强铝基复合材料的思路，阐述了制备的复合材料的潜在特点。     

浅谈日本胶合板热压机

浅谈日本胶合板热压机从日本进口的胶合板生产设备中，热压机、装卸板机具有结构设计合理、动作可靠、故障率低等优点。下面仅就我厂引进日本生产的热压机谈几点看法。１机架部分：该机机架采用焊接式整体结构，用厚１２ｍｍ的普通钢板在上下横梁处呈蜂窝状焊接。安装油缸...     

马来酸酐接枝聚丙烯对铝薄板/聚丙烯界面粘接强度的影响

研究了在砂纸打磨、硅烷偶联剂处理铝板表面两种条件下,马来酸酐接枝聚丙烯(MPP)含量对铝薄板/聚丙烯界面粘接剪切强度的影响.聚丙烯中不含MPP时,粘接剪切强度分别为3.44和4.57 MPa;添加MPP后,MPP的酸酐基团及其水解形成的羧基与铝板表面羟基、Al3 发生界面化学反应,粘接强度得以大幅提高.MPP含量为20%时,粘接强度分别达到最大值10.30和10.64 MPa.MPP含量继续增大时,在铝板表面形成较低分子量MPP的聚集区,且该区与MPP贫乏区之间的分子链缠结作用弱,导致铝板/聚丙烯的界面粘接强度随MPP含量增加而下降.     

Effect of Zr content on quench sensitivity of AlZnMgCu alloys

The effect of Zr content on quench sensitivity of AlZnMgCu alloys was investigated by mechanical properties testing and microstructure observations. The results show that with the increase of Zr the quench sensitivity relative to hardness and strength increases, while that relative to elongation decreases. From hardness and strength viewpoints, the low quench sensitivity is observed for the Zr-free and 0.05% Zr-containing alloys, which is quite quench sensitive from the ductility viewpoint. The largest quench sensitivity relative to hardness and strength is observed for 0.1% Zr-containing alloy, this is mainly due to large amount of high angle grain boundaries and incoherent Al3Zr dispersoids caused by recrystallization, which may efficiently promote heterogeneous precipitation during air quenching. More than 0.05% Zr can significantly decrease the quench sensitivity relative to ductility, which can be primarily attributed to recrystallization inhibiting and grain refining effects of Zr.     

微量Zr对Al-5.8Cu-0.3Mn合金焊接接头组织与性能的影响

采用4047焊丝对Al-5．8Cu-0．3Mn铝合金进行熔化极惰性气体保护焊，利用金相显微镜、透射电镜、显微硬度等检测分析手段研究了Zr对Al-5．8Cu-0．3Mn母材及焊接接头的力学性能和显微组织的影响。结果表明，Al-5．8Cu-0．3Mn合金中添加适量Zr元素可使母材强度提高30MPa，焊接接头强度提高50MPa，同时，细化了母材的再结晶组织和焊缝组织。焊接接头的强度低于母材强度，焊缝区是合金的薄弱处，热影响区强度降低是θ‘相粒子受热粗化所致。     

微量Mg和Ag在Al-5.8Cu-0.3Mn合金中的合金化作用

通过力学性能测试和显微组织观察研究了Al-5．8Cu-0．3Mn合金中微量Mg和Ag的合金化作用。结果表明，单独添加Ag和单独添加Mg均使合金θ′相的析出速度加快，析出的密度增加，合金的强化效果增强，但Mg的单独作用比Ag大；Mg和Ag共同加入产生的强化效应最大，这是由于Mg和Ag强烈相互作用在合金中析出Ω相强化所致。     

颗粒增强金属基复合材料的快速凝固制备方法及其特点

简述了几种主要的非快速凝固方法制备颗粒增强金属基复合材料所存在的主要问题，介绍了这种材料的快速凝固制备工艺方法，研究的概况及其特点。     

Al-12.6%Si薄带双辊快速凝固成形试验研究

运用双辊快速凝固方法将液态Ａｌ－１２．６％Ｓｉ合金直接制备成厚度为０．１￣０．５ｍｍ的薄带。介绍了这一方法的基本原理、特点和试验设备设计中的关键问题。辊面可控线速度Ｖｒ为２￣８．５ｍ／ｓ,薄带厚度正比于Ｖｒ＾－１／２。薄带组织为细小的初晶α－Ａｌ和极细小的（α－Ａｌ＋Ｓｉ）共晶体,塑性和抗拉强度得到明显改善．