共搜索到18973条信息,每页显示10条信息,共1898页。用时:0小时0分0秒765毫秒
双螺旋搅拌法制浆工艺参数对AZ91D合金半固态组织的影响 刘国钧1,朱光磊1,张志峰1,徐骏1 (1.北京有色金属研究总院国家有色金属复合材料工程技术研究中心,北京,100088) 摘要:双螺旋搅拌工艺制备了AZ91D合金半固态浆料,获得金属半固态加工要求的细小,等轴分布均匀的非枝晶组织.研究了熔体温度,搅拌速度和剪切时间对该组织的影响规律.结果表明:采用合适的搅拌工艺,可获得金属半固态加工要求的细小,等轴分布均匀的非枝晶组织.即降低降体温度,搅拌速度及适当剪切时间有利于细小球形晶粒的形成.加大搅拌速度及合理搅拌时间可以细化晶粒,主要是由于是高剪切作用下熔体获得一个非常均匀温度场,从而增加有效形核的缘故. 关键词:AZ91D镁合金; 半固态; 搅拌工艺; AZ91D Mg alloy; semisolid; stirring process; [全文内容正在添加中] ......
: A composite ceramic coating containing Y2O3-ZrO2-MgO (YSZ-MgO) was prepared on AZ91D magnesium alloy, which was immersed in Y(NO3)3 aqueous solution as pretreatment, by micro-arc oxidation (MAO... corrosion rate in 5% NaCl aqueous solution is lower than that of ZrO2-MgO and only about 8.5% of that of AZ91D magnesium alloy. After oxidation at 410 ℃, the mass gain of AZ91D magnesium alloy presents......
Electrochemical noise characteristics in corrosion process of AZ91D magnesium alloy in neutral chloride solution ZHANG Li-jun(张丽君)1, 2, ZHU Xu-bei(朱旭蓓)3, ZHANG Zhao(张 昭)2, 4...; Abstract: The corrosion process of AZ91D magnesium alloy in neutral 1% (mass fraction) sodium chloride aqueous solution......
experiments and the anodic polarization curves, the effects of composition of plating bath and temperature on corrosion behavior of magnesium alloy AZ91D in electroless nickel plating bath composed... alloy caused by SO2-4 in the bath is reduced in presence of F-. Key words: AZ91D magnesium alloy; bath corrosion; electroless nickel plating; nickel sulfate 镁合金是一种应用范围越来越广的轻金属材料. 由于其本身耐......
,R_p明显下降.MEA浓度控制在0.8<C_(MEA)<1.6g/L时获得的磷化膜的耐蚀性能最好. 关键词:AZ91D镁合金; 磷化膜; 耐蚀性能; 电化学测试; AZ91D magnesium alloy; phosphate coating; anti-corrosion performance; electrochemical tests; [全文内容正在添加中] ...乙醇胺添加剂对AZ91D镁合金表面磷化膜耐蚀性能的影响研究 徐淑强1,李青1,张冀2 (1.西南大学,化学化工学院,重庆,400715;2.海装重庆军代局,重庆,400042) 摘要:以磷酸盐化学转化膜为研究体系,采用动电位极化和交流阻抗分析方法及检测手段,研究乙醇胺添加剂及其浓度对AZ91D镁合金磷化膜耐蚀性能的影响.研究发现,(1)乙醇胺(MEA)作为添加剂可有效改善AZ91D镁合金表......
THE APPARENT VISCOSITY OF SEMI-SOLID AZ91D ALLOY AT STEADY STATE S.J.Yan1,W.M.Mao1,C.L.CuI1,Z.S.Zhen1,X.Y.Zhong1,A.M.Zhao1 (1.School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083,China) Abstract:The Rheological behavior of semi-solid AZ91D at steady state is studied using a Couettetype viscometer in the present paper. The results show......
Electroless nickel-plating on die cast magnesium alloy AZ91D JIA Su-qiu(贾素秋)1, JIA Shu-sheng(贾树胜)2, YAO Jun(姚 军)2 1. School of Materials Science and Engineering, Changchun University... Abstract: Electroless nickel-plating on die cast magnesium alloy AZ91D was investigated. Growth of the electroless nickel-plating coating was characterized using scanning electron microscopy. Corrosion......
Ce对AZ91D镁合金力学性能与阻尼性能的影响 张忠明1,郭学锋1,黄正华1 (1.西安理工大学,陕西,西安,710048) 摘要:为了提高AZ91D镁合金的力学性能与阻尼性能,利用OM(光学金相显微镜)和XRD分析了金属型铸造不同Ce含量AZ91D合金的显微组织和相组成,测试了室温力学性能,用悬臂梁技术测量了其阻尼性能.结果表明,AZ91D合金中加入一定量Ce后生成的A14Ce相被推移到生长界面,阻碍枝晶的自由生长,从而细化合金铸态组织;Ce能提高AZ91D合金室温抗拉强度,而对其屈服强度和延伸率影响不大,Ce能提高合金的阻尼性能;AZ91D-0.7%Ce合金晶粒细化效果佳,力学性能较理想,阻尼性能最高;合金的阻尼行为可用Granato-Lücke理论来解释. 关键词:AZ91D镁合金; Ce变质; 力学性能; 阻尼性能; [全文内容正在添加中] ......
Deposition of electroless Ni-P/Ni-W-P duplex coatings on AZ91D magnesium alloy CHEN Xiao-ming(陈晓明), LI Guang-yu(李光玉), LIAN Jian-she(连建设) Key Laboratory of Automobile Materials, Ministry... directly on AZ91D magnesium alloy by an acid-sulfate nickel bath. Nickel sulphate and sodium tungstate were used as metal ion sources and sodium hypophosphite was used as reducing agent. The coating......
;浸泡后期(80~120h),内层腐蚀反应达到平衡,膜层电阻等各项参数不再改变. 关键词:AZ91D镁合金; 磷化膜; 退化机制; 陈化时间; EIS; AZ91D magnesium alloy; phosphate coating; degradation mechanism; aging time; EIS; [全文内容正在添加中] ...陈化对AZ91D镁合金上磷化膜的影响及磷化膜退化机制的研究 徐淑强1,李青1,夏庆升2 (1.西南大学,化学化工学院,重庆,400715;2.海装重庆军代局,重庆,400042) 摘要:以磷酸盐化学转化膜为研究体系,采用交流阻抗(EIS)及红外(FT-IR)分析方法及检测手段,研究陈化时间对AZ91D镁合金磷化膜性能的影响及磷化膜的腐蚀退化机制.研究发现(1) EIS图谱和FT-IR图谱对......