材料期刊网，材料期刊，材料类期刊，材料期刊投稿

Local postweld heat treatment (PWHT)is usually performed when it is impractical to heat treat the whole vessel in a furnace, Many factors have an influence on PWHT procedures, such as size of the pipe,heated widths, insulation conditions, heating rates soak temperatures and hold times, material composition etc,. However up to now the influences these factors have on PWHT are not very clearly understood and different criteria for sizing the parameters can be found in different codes. This study provides a direct method to assess the effectiveness of local PWHT.An axisymmetrical model was used based on the thermal-visco-elastic-plastic Finite Element Method with the consideration of creep phenomena. By using this method both temperature and stress distributions can be simulated during whole local PWHT history. The computation results of temperature distributions and the strain histaries during local PWHT are compared with the experiments, and good agreements are obtained, Investigations show that the thermal stresses induced by local PWHT are much affected by creep behavior and the changes of Young's Modulus. The study of stress relief history shows that the stresses decrease quickly in the heating stage, then decrease slowly according to creep law in the hold stage and then studdenly increase when the cooling stage starts. The study shows the possibility that through a series of computations the effects of many factors can be assessed and the optimum parnmeters can be found. Compared with the heated widths based apon some applicable codes, it is found that a heated area of 2.5 on either side of the weld seems more reasonable.

关键词: postweld heat treatment , null , null , null

B180H1钢板成形性能研究

毕大森 , 武晋 , 张建 , 彭本栋

材料开发与应用 doi:10.3969/j.issn.1003-1545.2009.01.003

高强度烘烤强化(BH)钢是汽车覆盖件用的高强度钢板.本文通过试验对汽车用高强度钢板B180H1的力学性能、成形性能、烘烤硬化性能和抗凹陷性能进行了全面的研究,并与DC04钢板的各项性能进行了比较.使用NADDRG模型对B180H1钢的成形极限进行了预测.试验结果表明,B180H1的力学性能优于DC04,成形性能不低于DC04,且B180H1的烘烤硬化性能及抗凹陷性能方面均优于DC04.B180H1钢板的实冲壳体也具有良好的成形性能.

关键词: 汽车轻量化 , 高强度钢板 , 烘烤硬化 , 成形性能 , 抗凹陷性

层状H1-xNb1-xW1+xO6固体酸的制备与表征

谢慕华 , 丁志福 , 李瑞

材料导报

采用高温固相法合成Li1-xNb1-xW1+xO6 (x=0.1,0,-0.1),通过H+交换制备出相应的固体酸H1-x-Nb1-xW1+xO6.采用XRD和FT-IR技术表征固体酸的物相和层板骨架结构,NH3-TPD方法表征其酸性特征.结果表明,3种酸样品的物相相同,但它们的主晶面(002)面间距略有变化.与HNbWO6中的NbO6和WO6八面体结构单元相比,H0.9Nb0.9 W1.1O6和H1.1 Nb1.1 W0.9 O6中的NbO6和WO6八面体发生变形.3种酸样品均有两种不同强度的酸位,它们的弱酸位强度基本相等,强酸位强度大小顺序为HL1 Nb1.1W0.9O6 ＞H0.9 Nb0.9 W1.1 O6＞ HNbWO6,两种酸位的酸量大小顺序均为H1.1 Nb1.1 W0.9 O6＞ HNbWO6＞ H0.9Nb0.9W1.1O6.

关键词: 层状化合物 , 铌钨酸 , 结构 , 酸性

a-Si:H/a-Si_(1-x)C_x:H 多层膜的电学和光学性质

彭启才 , 周心明 , 蔡伯埙

材料研究学报

采用等离子体辉光放电单室系统制备的a-Si:H/a-Si_(1-x)C_x:H 多层膜结构具有低的暗电导和高的光电导特性,且不同于单层膜,有明显的S-W 效应。随着子层厚度L 减小,多层膜曝光态(B)的暗电导率σdB 较退火态(A)的σdA 减小快,即光诱导衰退程度增大,而光电导无明显变化。本文还测定了此多层膜结构的光能隙E_g,得到随子层厚度减小“蓝移”的结果。用一维单量子阱模型作了讨论,实验值与理论计算符合较好。

关键词: a-Si:H/a-Si_(1-x)C_x:H , superlattice , amorphous semiconductors electrical properties , optical properties , null

Huazhong University of Science and Technology(H.U.S.T)

材料科学技术（英文）

关键词:

TS-1/H2O2体系催化二乙胺氧化竞争反应

邓秀娟 , 申璐 , 张硕 , 刘月明

催化学报 doi:10.3724/SP.J.1088.2011.10543

系统研究了TS-1/H2O2催化二乙胺(DEA)氧化制备二乙基羟胺(DEHA)的反应规律,考察了DEA氧化及DEHA氧化反应之间的竞争关系.结果表明,H2O2以连续方式进料时,DEA转化率及H2O2有效利用率明显提高,而反应体系中DEA/H2O2的摩尔比对DEHA选择性的影响较大.TS-1既可催化DEA的氧化,又可催化产物DEHA的进一步氧化.

关键词: 钛硅分子筛 , 过氧化氢 , 二乙胺 , 氧化 , 二乙基羟胺

掺铒a-SixC1-x-H薄膜的发光特性

卞留芳 , 张春光 , 陈维德 , 许振嘉 , 屈玉华 , 刁宏伟

中国稀土学报

用等离子体增强化学气相沉积(PECVD) 的方法,以固定的氢气(H2)流量和不同的硅烷(SiH4)和甲烷(CH4)流量比沉积了一系列的氢化非晶SiC(a-SixC1-x-H)膜.用这种宽带隙的a-SixC1-x-H材料作为掺铒的基体材料,通过离子注入的方法得到掺铒的a-SixC1-x-H(a-SixC1-x-H:Er)膜.注入以后的样品经过不同温度的退火.用X射线光电子能谱(XPS)、红外吸收光谱(IR)、拉曼散射谱(Raman)等技术研究不同的SiH4/CH4流量比和退火温度对a-SixC1-x-H:Er发光强度的影响.结果表明,高温退火引起了膜中C的分凝,对铒的发光是不利的.通过低温和室温下铒发光强度的比较,表明这种材料具有较弱的温度猝灭效应.

关键词: Er , SiC , 硅基材料 , 发光 , 稀土

STUDY ON THE THREESTAGE CREEP OF THE DD3SINGLE CRYSTAL SUPERALLOY

Author X.A. Zhang1) , H.Q. Xia1) , Z.T. Wu1) , Y.F. Han1) , R. Shi2) and G.X. Hu2) \= 1) Mechanical Properties Laboratory , Beijing Institute of Aeronautical Materials , Beijing 100095 , China2) The State Education Commission Open Research Laboratory for High Temperature

金属学报(英文版)

Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, ChinaManuscript received 18 October 1998 The threestage creep behavior of DD3 single crystal superalloy had been studied. The results show that the creeprupture properties of DD3 single crystal satisfy the requirements for high performance turbine blade application. The influence of crystal orientation on the creeprupture property of DD3 single crystal was tested and discussed. An engineering criterion to evaluate the regimes of secondary and tertiary creep is proposed, and this method gives a reasonable result for practical applications. The fractography and TEM micrography of the tested specimens had been studied, and it is determined that the glidecontrolled creep is the basic creep mechanism of DD3 single crystal at intermediate temperature, but the thermally activated processes become dominant at higher temperature.

关键词: threestage creep curve , null , null , null

α-Si1-xCx:H薄膜材料的弹性反冲探测分析

周平 , 路秀琴 , 郭继宇 , 赵葵 , 吴伟明 , 隋丽 , 倪嵋楠 , 梅俊平 , 罗红兵 , 刘建成

原子核物理评论 doi:10.3969/j.issn.1007-4627.2004.03.014

介绍在中国原子能科学研究院HI-13串列加速器上, 对α-Si1-xCx∶H薄膜样品进行弹性反冲探测分析的方法和结果.用该加速器提供的高品质127I束流轰击α-Si1-xCx∶H薄膜材料样品, 用ΔE(gas)-E(PSD)望远镜探测器, 在前角区(30°角)测量从该样品中反冲的各元素的能谱.然后用离子束分析(IBA)程序SIMNRA 对能谱进行拟合, 得到样品中H, C和Si的比分及深度分布.

关键词: 弹性反冲探测分析 , 非晶氢化硅碳薄膜 , ΔE-E望远镜探测器