材料期刊网

锂对低Cu/Mg比Al--Cu--Mg--Ag合金时效特性的影响

陈志国 , 郑子樵 , 王芝秀 , 李世晨

材料研究学报

通过时效硬化曲线的测量、室温拉伸实验以及时效组织的电镜观察, 研究了添加锂对低Cu/Mg比Al--Cu--Mg--Ag合金时效特性的影响. 结果表明, 在Al--4.0Mg--1.5Cu--0.4Ag合金中添加锂, 可以加速合金的时效进程, 但其时效硬化效果并不能简单地随着含锂量的增加而逐步加强, 只有当锂含量达到2.0\%(质量分数)时, 才表现出显著的时效硬化与强化效果. 含2.0\%Li的Al--4.0Mg--1.5Cu--0.4Ag合金中$Z$相、$\delta^{\prime}$以及 $\delta^{\prime}$/$\beta^{\prime}$复合粒子的弥散析出是产生显著时效硬化与强化的原因.

关键词: 金属材料 , Al alloy , ageing , microstructure , lithium

DZ40M钴基高温合金950℃长期时效后的组织与性能

姜文辉 , 姚向东 , 管恒荣 , 胡壮麒

金属学报

研究了新近开发的一种定向凝固钴基高温合金DZ40M950℃长期时效后的组织与性能．结果表明，合金时效后室温强度提高，塑性降低980℃，83MPa持久性能提高，而816℃，215MPa持久性能下降．在时效过程中，初生碳化物M7C3和MC缓慢分解，细小的M23C6在基体中大量析出，M6C在一些M7C3表面生成．分析认为，合金性能变化主要归因于M(23)C6沉淀析出初生碳化物M7C3和MC分解，释放出碳原子，促进M(23)C6沉淀反应、M6C形成是由于钨的局部偏聚所致．

关键词: 钴基高温合金 , Co-base superalloy , ageing , carbide transformation , mechanical property

Effect of Phosphorus on Mechanical Properties and Thermal Stability of Fine-grained GH761 Alloy

Shulin Yang

材料科学技术（英）

The effect of phosphorus on mechanical properties and thermal stability of fine-grained GH761 alloy has been investigated. The results show that, when the content of phosphorus is in the range of 0.0007%-0.040%, there are no significant effects on the tensile properties. Phosphorus strongly affects the stress rupture life. The content of 0.023% P results in the longest life in this experiment. Compared with that of the alloy with 0.0007% P, the life is increased more than 2 times in the alloy with 0.023% P. After ageing at 700°C for 1000 h, the life reduced to some extent. However, phosphorus exhibits the similar effect on the life as before ageing. The tensile properties of the alloy are not influenced by long term ageing obviously. The present results suggested that the optimum content of phosphorus is 0.023%. The phosphorus with this content can optimize the precipitates at the grain boundaries and prevent the excessive growth of the precipitates. The combining mechanical properties of GH761 alloy can be largely improved by phosphorus addition combined with grain refinement.

关键词: Phosphorus

Effect of Phosphorus on Mechanical Properties and Thermal Stability of Fine-grained GH761 Alloy

Shulin Yang

材料科学技术（英）

The effect of phosphorus on mechanical properties and thermal stability of fine-grained GH761 alloy has been investigated. The results show that, when the content of phosphorus is in the range of 0.0007%-0.040%, there are no significant effects on the tensile properties. Phosphorus strongly affects the stress rupture life. The content of 0.023% P results in the longest life in this experiment. Compared with that of the alloy with 0.0007% P, the life is increased more than 2 times in the alloy with 0.023% P. After ageing at 700°C for 1000 h, the life reduced to some extent. However, phosphorus exhibits the similar effect on the life as before ageing. The tensile properties of the alloy are not influenced by long term ageing obviously. The present results suggested that the optimum content of phosphorus is 0.023%. The phosphorus with this content can optimize the precipitates at the grain boundaries and prevent the excessive growth of the precipitates. The combining mechanical properties of GH761 alloy can be largely improved by phosphorus addition combined with grain refinement.

关键词: Phosphorus

桐马环氧玻璃丝粉云母绝缘材料的耐盐雾湿热老化特性

付强 , 孔繁荣 , 陈庆国

复合材料学报

为了研究海洋能电机主绝缘材料耐盐雾湿热老化能力,对电机多胶模压(Resin Rich Molding,RRM)桐马环氧玻璃丝粉云母(Tong ma Epoxy Glass Fiber Power Mica,TEGM)绝缘材料进行模拟海洋气候的盐雾湿热老化试验,测试了不同老化周期下材料的吸水率变化,并结合扫描电子显微镜(Scanning Electron Microscope,SEM)的观测结果分析了材料老化前后微观形貌的变化.利用宽频介电阻抗谱仪测试不同老化周期和不同测试温度下的TEGM绝缘材料的频域介电参数变化,并运用电介质极化理论分析老化前后的微观结构形态变化和宏观介电性能之间的关系.研究结果表明,TEGM绝缘试样老化过程中的吸水性呈现快速吸湿、缓慢吸湿和饱和吸湿3个阶段;随着老化时间的延长,材料相对介电常数和介质损耗因数呈上升趋势,利用频域介电谱(Frequency Domain Spectroscopy,FDS)曲线可较好反映绝缘材料的老化状态;通过对测试数据的拟合,得到老化绝缘材料的介电参数与材料吸水率在低频下存在的二次方程关系.

关键词: 盐雾湿热老化 , 频域介电谱 , 多胶模压 , 桐马环氧玻璃丝粉云母 , 绝缘材料 , 老化 , 吸水率

Improving the Mechanical Properties of Copper

M.C. Somani , L.P. Karjalainen

金属学报(英文版)

Systematic physical simulation of thermo-mechanical processing routes has been applied on a Gleeble 1500 simulator to four copper alloys (mass %) Cu-0.57Co-0.32Si, Cu-0.55Cr-0.065P, Cu-0.22Zr-0.035Si and Cu-1.01Ni-0.43Si aimed at clarifying the influences of processing conditions on their final properties, strength and electrical conductivity. Flow curves were determined over wide temperature and strain rate ranges. Hardness was used as a measure of the strength level achieved. High hardness was obtained as using equal amounts (strains 0.5) of cold deformation before and after the precipitation annealing stage. The maximum values achieved for the Cu-Co-Si, Cu-Cr-P, Cu-Zr-Si and Cu-Ni-Si alloys were 190, 165, 178 and 193 HV5, respectively. A thermo-mechanical schedule involving the hot deformation-ageing-cold deformation stages showed even better results for the Cu-Zr-Si alloy. Consequently, the processing routes were designed based on simulation test results and wires of 5 and 2mm in diameters have been successfully processed in the industrial scale.

关键词: copper alloys , null , null

15-5PH马氏体时效钢的工艺性能

李伟 , 杜楠 , 樊兆宝

兵器材料科学与工程 doi:10.3969/j.issn.1004-244X.2010.01.022

研究15-5PH钢482～621 ℃时效处理时尺寸变化率,焊接系数和冷却介质对固溶和时效硬度的影响.482℃时效处理时尺寸变化率在万分之十一以内,焊接系数0.969,固溶处理后水冷、油冷、空冷3种处理方式中,水冷固溶状态的硬度最低而时效后的硬度最高,空冷固溶状态的硬度最高而时效后的硬度最低.

关键词: 15-5PH钢 , 时效 , 固溶 , 尺寸变化率

陶瓷改性复合绝缘子材料的力学性能研究

易春芳 , 梁培松 , 梁英 , 刘云鹏

绝缘材料

为解决每年大量退运陶瓷绝缘子的瓷体处理问题，结合陶瓷绝缘子的优点及其化学成分，利用废旧陶瓷绝缘子瓷体研磨成粉末后改性硅橡胶而制得陶瓷改性复合绝缘子材料，通过测试改性硅橡胶的拉伸强度、撕裂强度和硬度，并利用SEM电镜扫描及红外光谱进行分析，对比研究了陶瓷粉添加量对硅橡胶力学性能的影响。结果表明：一定比例的陶瓷粉可以替代部分氢氧化铝微粉和气相法白炭黑，且对硅橡胶的力学性能有明显的改善。

关键词: 硅橡胶 , 复合绝缘子 , 老化 , 退运 , 陶瓷

Effect of Ageing at 700 ℃ on Microstructure and Mechanical Properties of S31042 Heat Resistant Steel

钢铁研究学报(英文版)

关键词:

尼龙老化机理研究进展

蔡琤 , 易国斌 , 陈旭东

合成材料老化与应用

概述了环境(如光、热和应力)对尼龙老化的影响,提出了尼龙老化的一些主要机理.重点介绍了尼龙老化实验的分析测试方法,并在尼龙老化研究方法的基础上,展望了尼龙老化及防护措施的研究动向和发展趋势.

关键词: 尼龙 , 老化 , 机理 , 老化分析