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MICROSTRUCTURE AND FORMATION MECHANISM OF LASER CLAD Ni60ACOATING

C.Z. Chen1 , 2) , T.Q. Lei2) , D.W. Cui1)and J.H. Yu1) 1) College of MaterialScience and Technology , Shandong University of Technology , Jinan 250061 , China2) College of MaterialScience and Technology , Harbin Institute of Technology , Harbin 150001 , China

金属学报(英文版)

The microstructure and formation mechanism of laser clad Ni60 Acoating were studied by meansof XRD, SEM, TEMand EDAXetc. Theresultsshow thatthe microstructureofthe coatingiscontrolled bytheratiooftemperature gradient Gand solidification speed υ( G/υ)atthesolid liquidinterface. Attheinterfaceof molten pool/substrate, G/υisquitelarge,and Ni basedsolid solutionsgrowingintheform oflow speed planar grain boundary form abonding belt. With the advancement of the solid liquid interface, G/υdecreases, and a bonding zone mainly composed ofcomplex cellulareutecticsof Ni+ M23( CB)6 and Ni+ Ni3Bisformed when G/υisstilllargeenough. Further decrease willlead to a clad layerthat exhibitscellular and dendritic Ni basedsolidsolutions,dendriticor discontinuousnetwork M7( CB)3 and complex eutectics( Ni+ M23( CB)6 and Ni+ Ni3 B) between them .

关键词: microstructure , null , null , null

X70管线钢J1d和K1a与V型缺口Ak关系研究

朱杰武 , 柳永宁 , 许雁 , 冯耀荣

机械工程材料 doi:10.3969/j.issn.1000-3738.2005.06.007

在不同温度下测试了X70管线钢动态断裂韧度K1d、J1d和止裂韧度K1a以及夏氏V型缺口冲击韧度Ak,对三者的关系进行了分析.结果表明:温度和加载速率都对断裂韧度产生影响;加载速率变化引起的韧-脆断裂转变具有热激活特征,在热激活分析基础上,在应力强度因子速率K=15 MPa·m1/2s-1条件下,得出断裂韧度、止裂韧度和冲击韧度三者的关系:Ak=4.84×106T-2.8K1d(或K1a).可以用小试样Ak数据计算得到K1d和K1a.

关键词: 管线钢 , 断裂韧度 , 止裂韧度 , 韧-脆断裂转变

H_2气氛保护热处理1J50组织结构与性能的研究

孙建春 , 盛光敏 , 陈登明 , 周安若 , 朱光俊

功能材料

1J50软磁合金的性能主要是通过H_2热处理获得的,在1130℃和H2气氛保护下对冷轧态1J50软磁合金进行了热处理.运用MATS-2010SA软磁测试仪对处理前后1J50软磁合金的磁性能进行了检测,运用金相显微镜、XRD等手段对处理前后1J50软磁合金的组织结构进行了分析.结果表明,通过H_2热处理,1J50软磁合金的矫顽力显著降低,起始磁导率和最大磁导率提高;组织结构发生明显变化,冷轧态1J50软磁合金组织为孪晶奥氏体,平均晶粒尺寸为200μm,处理过后,晶粒显著长大,平均晶粒尺寸为100μm;由于在600℃时采取了快冷,处理后1J50软磁合金中未出现大量FeNi相和FeNi_3相.

关键词: H2热处理 , 1J50 , 组织结构 , 性能

高分子负载CuI催化"一锅法"合成1,2,3-三唑化合物

王亮 , CAI Chun

应用化学 doi:10.3969/j.issn.1000-0518.2008.08.015

制备了高分子负载CuI催化剂,将其应用于1,3-偶极环加成反应.制备了1,2,3-三唑类化合物,考察了溶剂、碱、催化剂用量、反应气氛对反应的影响,确定了较佳的反应条件.研究表明,以PEG/H2O为溶剂在室温下就能有效地催化反应,生成单一的1,4取代的三唑化合物,同时,进一步考察了不同底物的反应效果.苄基和烯丙基类卤代烃活性较高.反应8 h得率为72%～94%;饱和卤代烃经延长反应时间有中等以上收率;芳烃反应活性较差,碘代芳烃在85℃反应24 h,只有中等收率,而溴苯根本不发生反应.催化剂经过简单的过滤洗涤后可重复使用4次.显示了较好的催化活性.

关键词: 高分子负载催化剂 , 环加成反应 , 三唑

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

应力对1J79软磁合金强场磁导率的影响

尔延徽 , 毛昌辉 , 杨志民 , 杜军

稀有金属 doi:10.3969/j.issn.0258-7076.2007.06.008

采用8232型B-H交流回线仪对受力前后的1J79软磁合金在不同场强和频率下磁导率的变化进行了研究, 通过XRD对材料受力前后微观结构变化进行了分析. 研究表明: 场强在1～10 A·m-1范围内, 直流条件下受应力1J79合金的相对磁导率远低于不受应力1J79合金的相对磁导率; 交流条件(5～30 kHz)下受应力1J79合金的相对磁导率低于不受应力1J79合金的相对磁导率, 但低于直流条件下的降低幅度. 1J79合金受力后, 使有利于磁性能(111)晶面取向大大减少, 是合金受力后相对磁导率下降的主要原因.

关键词: 应力 , 强场 , 1J79软磁合金 , 相对磁导率

One-Dimensional (1-D) Nanoscale Heterostructures

Guozhen SHEN , Di CHEN

材料科学技术（英文）

One-dimensional (1-D) nanostructures have been attracted much attention as a result of their exceptional properties, which are different from bulk materials. Among 1-D nanostructures, 1-D heterostructures with modulated compositions and interfaces have recently become of particular interest with respect to potential applications in nanoscale building blocks of future optoelectronic devices and systems. Many kinds of methods have been developed for the synthesis of 1-D nanoscale heterostructures. This article reviews the most recent development, with an emphasize on our own recent efforts, on 1-D nanoscale heterostructures, especially those synthesized from the vapor deposition methods, in which all the reactive precursors are mixed together in the reaction chamber. Three types of 1-D nanoscale heterostructures, defined from their morphologies characteristics, are discussed in detail, which include 1-D co-axial core-shell heterostructures, 1-D segmented heterostructures and hierarchical heterostructures. This article begins with a brief survey of various methods that have been developed for synthesizing 1-D nanoscale heterostructures and then mainly focuses on the synthesis, structures and properties of the above three types of nanoscale heterostructures. Finally, this review concludes with personal views towards the topic of 1-D nanoscale heterostructures.

关键词: Nanostructures , Heterostructures , One-dime