Liang Minjie , Chen Zheng , Wang Yongxin , Zhang Jixiang , Lai Qingbo
2008, 37(2).
Abstract:采用三元微观离散格点形式的相场模型,对Ni75Al25-xFex合金γ'相的原子占位、浓度和长程序参数等进行了模拟计算.结果表明:γ'相沉淀析出为等成分有序化兼失稳分解机制;在γ'相内,随Fe含量的增加,Fe原子在β位的占位呈明显的上升趋势,Al原子反之,且发现有少量Ni原子占据β位.另一方面,在α格点,Fe原子的占位只呈现略微的增长,Al原子几乎不变,而Ni原子则略微下降:β位主要由Al,Fe原子共同占据,形成的γ'相是Ni3(AlFe)单相.
Xin Guoqiang , Yang Xueqin , Dong Nan , Tian Xiubo , Yang Shiqin
2008, 37(2).
Abstract:采用PⅢ对Ti6A14V合金进行表面处理,温度控制在300~400℃之间,利用小掠射角X射线衍射技术(GXRD)、扫描电镜(SEM)研究不同工艺条件下的相结构和表面形貌,并且测量处理后试样的显微硬度、摩擦磨损性能.结果表明:试样表面形成了金红石相,且试样表面变得粗糙;在390℃处理后的试样硬度提高27%,抗磨损性能提高.
Sun Jibing , Wang Hairong , An Yaqin , Cui Chunxiang , Han Dan
2008, 37(2):189-194.
Abstract:In this paper, the types and development of long persistence luminescent materials including sulphide long persistence materials, alkali-earth aluminate long persistence materials and silicate long persistence materials etc. are introduced. The recent progress and luminescent mechanism are summarized, and the preparation methods are reviewed. Finally, the future development directions and latent application fields of the long persistence luminescent materials are discussed.
Wang Yanzhi , Zhao Minshou , Li Shucun
2008, 37(2):195-199.
Abstract:The recent progress on study of composite hydrogen storage alloy as negative electrode of Ni/MH battery is reviewed, focusing on the major component, main methods of preparation, analysis and characteristic methods, micro-structural characteristics, electrochemical performance, and mechanism of hydriding and dehydriding. The composites are classified into five kinds based on the major component, e.g. AB5 type rare-earth hydride material, AB2 type hydride material with laves phase, A2B, AB type Mg-based hydride material, solid solution hydrogen storage alloy with BCC structure and new type La-Mg-Ni-based hydride material with stacked structure, respectively. The existing problems on research of the composite hydride materials are pointed out and the prospect of the composite development has been viewed.
Sun Qiu , Cheng Haitao , Wang Fuping
2008, 37(2):200-204.
Abstract:An increasing interest in PZT ferroelectric memories is presented for their commercial applications in recent years, but fatigue behavior of PZT capacitors has been a critical problem in commercial applications for FRAM devices. Changing of electrode materials of PZT capacitors is an effective method to overcome the fatigue behavior of PZT capacitors. In this paper the structure, properties and characteristics of electrode materials for PZT thin films are introduced systematically. The effect of different electrode materials on structure and ferroelectric properties of PZT thin films are compared. The mechanism how to improve the ferroelectric properties of PZT capacitors via conducting metal oxide electrodes are discussed. The main problems and directions of development of electrodes are presented.
Zhang Jixiang , Chen Zheng , Wang Yongxin , Liang Minjie , Lai Qingbo
2008, 37(2):210-214.
Abstract:基于三元体系的微观相场动力学模型,从原子层次上模拟了Ni-11at%Al-7at%Cr合金在873 K预时效,1023 K再时效的组织演化过程,结合原子图像,计算了有序相内序参数分布和体积分数随时间的变化,并与1023 K下的单级时效工艺进行了对比.研究结果表明:两种工艺条件下. 均析出单一的LI2结构有序相,分级时效的沉淀机制为非经典形核长大与失稳分解的混合机制;单级时效的沉淀机制为失稳分解机制:分级时效获得的沉淀相呈45°方向倾斜排列的弥散颗粒状,单级时效获得的沉淀相呈45°方向倾斜的条纹状;分级时效工艺下孕育期缩短,达到平衡时,二者的体积分数相等.
Zhang Limin , Geng Xingguo , Li Jinshan , Fu Hengzhi , Su Kehe , Zhou Lian
2008, 37(2):215-218.
Abstract:用电子密度泛函方法(DFT)对YBa2Cu3O7晶胞39个原子模型系统计算了其能隙随温度的变化规律,并在能隙计算基础上,应用电子比热的双极化和热激发的极化子模型计算了电子比热及其系数随温度的变化关系.计算结果表明:超导能隙在超导临界温度点93 K附近有不为零的极小值;能隙曲线中的几个转折温度点依次分别与Tc,T*和T0相对应;在Tc~T*温度范围,超导态消失,但有反铁磁自旋相干引起的自旋能隙的存在;在T*~T0温度范围,有周期性条纹相产生的电子密度波引起的能隙的存在;在T=T0,电子比热系数发生了从增大到减小的转折变化.
Cao Honghong , Chen Qiang , Wang Tianmin
2008, 37(2):219-222.
Abstract:从第一原理角度,用基于密度泛函理论(DFT)的全电势线性缀加平面波法(FLAPW)和广义梯度近似(GGA),计算了掺Sn锐钛矿相 TiO2的晶格优化结构和电子结构.结果表明:掺Sn以后晶胞体积明显增大,在z方向有伸长的趋势;掺Sn锐钛矿相TiO2典型晶面的电子密度分布与纯的锐钛矿相TiO2的比较表明,掺杂后的Sn-O键比原来的Ti-O键强;掺Sn锐钛矿相TiO2的能带结构图表明,掺杂后仍为间接带隙的半导体,与未掺杂时比较,能隙减小了0.24 eV,与实验趋势相符.
Zhou Xiaolong , Chen Jingchao , Cao Jianchun , Sun Jialing , Zhang Kunhua , Du Yan , Chen Yiwu
2008, 37(2):223-226.
Abstract:The finite element simulation was adopted for severe plastic deformation of reactive synthesis AgMeO composites. The homogenization degree of microstructure was researched by simulation and experiment in same true strain condition for AgSnO2 and AgCuO composites. The results showed that the model of finite element, according to the sinter microstructure of AgMeO composites, can effectively simulate the program of severe plastic deformation. The results of simulation and experiment were consistent. From the result of simulation and experiment, the phenomena of microstructure delaminating was inevitable due to the clustering of reinforce phase in the deformation. The homogenization of microstructure can be obtained through the bigger deformation strength.
2008, 37(2):227-231.
Abstract:通过拉伸试验研究了不同组织结构不锈钢纤维织物的电阻与应变之间的关系,观察到不锈钢织物的电阻变化依赖于不同的组织结构,线圈转移少、接触电阻变化大的织物有利于提高电阻响应的灵敏度和重现性.另外不锈钢纤维织物的相对电阻变化还与加载条件如最大循环应变、加载速率等相关.
Xin Shewei , Zhao Yongqing , Zheng Weidong , Yang Haiying , Wu Huan , Li Qian
2008, 37(2):232-235.
Abstract:Two alloys of Ti-25V-15Cr-0.2Si and Ti-25V-10Cr-0.2Si with different content of alloying element Cr after different thermal exposure were studied. The results show that Cr could refine the grain of Ti-V-Cr bum resistant alloy, and strengthen its mechanical property at room temperature. With the decrease of Cr, the amount of the second precipitation phase is reduced and the thermal stability of alloy becomes better, which can be interpreted by the eutectoid feature of alloying element Cr in titanium alloy.
Chen Yuyong , Yu Hongbao , Zhang Deliang , Kong Fantao
2008, 37(2):236-239.
Abstract:采用低温高能球磨法制备了两种Ti/Al复合粉末,粉末组成为Ti-47Al(at%),Ti-45Al-2Cr_2Nb-1B-0.5Ta(at%).研究两种粉末在球磨过程中显微组织结构演化、形貌变化.结果表明,降低球磨温度能够有效控制球磨颗粒尺寸,低温条件及合金元素共同作用可以获得高质量的细晶均匀化复合结构粉末.在低温(-140-5)℃不加过程控制剂条件下球磨12 h,Ti-45Al-2Cr-2Nb-1B-0.5Ta(at%)粉末粒度得到有效细化,表现出精细均匀化复合结构粉末,Ti与Al晶粒尺寸分别约为16 nm,9 nm.在相同条件成分为Ti-47Al(at%)球磨5.2 h,Ti与Al元素没有很好复合及成分均匀化,两种成分球磨条件下均未有新相生成.在不加过程控制剂条件下,低温环境球磨和合金元素添加对机械合金化过程具有十分重要影响.
Wang Zhanyong , Zhou Bangxin , Ni Jiansen , Xu Hui , Wang Xianying , Fang Yongzheng , Jin Minglin
2008, 37(2):240-244.
Abstract:Coercivity is improved, while remanence is decreased for the annealed ribbons with the increase of rare earth content, the coercivity for ribbons reaches 955 kA/m upon 10at% in rare earth content and 12 m/s in wheel speed. Wheel speed almost has no effect on magnetic properties of ribbons with 9,5at% in rare earth. The amorphous formation ability and thermal stability are improved for as-spun ribbons upon Dy or Pr substitution for Nd element. Coercivity and Curie temperature are improved and remanence is decreased slightly for ribbons upon Dy substitution for Nd element. But for ribbons with Pr substitution for Nd element, both of coercivity and remanence are increased slightly .
Zhang Yanghuan , Zhao Dongliang , Han Xiaoying , Dong Xiaoping , Guo Shihai , Wang Xinlin
2008, 37(2):245-250.
Abstract:在不同的球磨时间下,应用机械合金化法制备出Mg2-xZrxNi(x=0,0.15,0.3,0.45,0.6)电极合金.系统地测试了合金的微观结构及电化学性能,研究了球磨时间对合金微观结构及电化学性能的影响.XRD及 TEM的分析结果表明,合金中的非晶相随球磨时间的延长而增加.电化学测试的结果显示,随球磨时间的增加,合金的循环稳定性及放电电压特性得到显著改善.球磨时间对合金容量的影响与合金的成分相关,对于x≤0.3的合金,其放电容量随球磨时间的延长而单调增加;而对于x>0.3的合金,放电容量随球磨时间的增加有一个极大值.
Ma Li , Hu Rui , Li Jinshan , Kou Hongchao , Fu Hengzhi , Zhou Lian
2008, 37(2):251-254.
Abstract:利用定向凝固技术制备了取向良好的YBCO棒材,其a-b晶面与提拉方向的夹角小于5°.为研究YBCO生长的各向异性及其定向凝固机制,分别通过空淬及炉冷的方式获取了熔体生长的YBCO晶粒形貌及固液界面形貌.YBCO晶粒呈现片层状结构,其长厚比约为2~5.晶体生长的固液界面清晰反映出了外延生长的特征.基于上述结果,讨论了YBCO的定向凝固机制,认为YBCO的定向凝固是由择优生长及外延生长两阶段构成,这很好地解释了本文的试验结果.
Xiao Feng , Liu Lanxiao , Fang Liang , Yang Renhui , Fu Ya , Zhao Hongkai
2008, 37(2):255-258.
Abstract:Ni-Co高温合金广泛用于生产燃气涡轮机叶片和热交换器等工作于高温和腐蚀环境的零部件,采用改良静滴法测定了1773~1873K温度范围内熔融Ni,Ni-(5~10)%Co合金在Al2O3基板上Ar 3%H2气氛下的表面张力.熔融Ni,Ni-(5~10)%Co合金的表面张力随着温度的升高而降低.在此基础上采用Butler模型推导了表面张力随温度与浓度的变化,计算了合金体系中元素的偏聚.结果表明,Co在合金表面的浓度低于在体相的浓度.
Lou Xueming , Sun Wenru , Guo Shouren , Hu Zhuangqi
2008, 37(2):259-263.
Abstract:研究了 IN718高温合金在650℃下的熔盐(75%Na2SO4 25%NaCl)热腐蚀行为及其对合金力学性能的影响.研究表明,IN718合金热腐蚀层分为两层,外层由Fe3O4,FeCr2O4和Cr2O3等氧化物组成,内层由Ni和Ni的硫化物组成.热腐蚀过程中S沿晶界快速扩散并在晶界形成硫化物.IN718合金在650℃,100 h浸盐热腐蚀预处理后,室温拉伸性能和650℃拉伸强度变化不大,合金在650℃拉伸塑性略微降低,但650℃,700 MPa持久性能显著降低,其主要原因是S降低晶界强度,同时外加应力提高腐蚀速率.
Wang Dahui , Wu Yanjun , Yan Ruxu , Luo Yongchun , Kang Long
2008, 37(2):264-268.
Abstract:采用电子探针(EPMA)、X射线衍射(XRD)和电化学测试研究了在6 mol/L KOH电解液中添加Cu(OH)2对La2MgNi7.5Co1.5贮氢合金电极电化学性能的影响.结果表明,合金电极外表面上被镀上Cu膜,Cu膜的厚度和致密性随充放电循环次数的增加而增加,合金电极表面形成致密性Cu膜,可以有效地抑制电极内部贮氢合金的氧化,但对贮氢合金颗粒粉化的抑制作用不明显.在电解液中添加Cu(OH)2,增加了La2MgNi7.5Co1.5合金电极的活化次数,降低了该合金电极的高倍率放电性能,但对合金电极的最大电化学放电容量没有负面影响.此外,利用电沉积方法在电极表面镀Cu膜能够明显改善该合金电极的电化学循环稳定性.
Wang Dongtian , Wei Jie , Liu Jiahui
2008, 37(2):269-272.
Abstract:为了改善铂基催化剂氧化甲醇的催化活性,采用循环伏安法制备了聚苯胺修饰分散铂电极(Pt-Pan/Pt)、聚苯胺和磷钼酸共同修饰分散铂电极(PMo12-Pt-Pan/Pt).并用循环伏安法研究了制备电极在0.5 mol·L-1H2SO4溶液中的电化学行为以及对甲醇氧化的催化效果.结果表明:PMo12-Pt-Pan/Pt电极对甲醇氧化具有很高的催化活性.PMo12-Pt-Pan/Pt电极对甲醇氧化的最大电流是33.43 mA,是Pt/Pt电极的1.37倍.催化活性的提高来源于聚苯胺和磷钼酸与铂的协同作用.
Zhang Xiyan , Li Cong , Shi Minghua , Liu Nianfu , Qiu Shaoyu , Zhang Qiang
2008, 37(2):273-276.
Abstract:建立了纳米结构组织锆-4合金腐蚀速率.晶粒尺寸关系模型,计算了高温下纳米组织锆-4合金和腐蚀速率曲线,并与纳米组织锆-4合金在400℃水蒸气中的腐蚀试验数据进行了对比.结果表明:与普通晶粒相比,纳米晶粒尺寸下锆合金的速率低于普通晶粒锆-4合金的腐蚀速率,随着纳米晶粒尺寸的减小,锆-4合金的腐蚀速率也降低;同时,纳米化组织处理推迟了锆-4合金氧化转折时间,使其抗氧化性能得到了提高.
Liu Xuebin , Ma Mo , Wang Xiufeng , Wu Xueqing , Lin Jianguo , Wen Cuie
2008, 37(2):277-280.
Abstract:用粉末烧结法制备了相对密度为0.2的开孔泡沫纯钛材料,并在室温20~600℃温度范围内,对其压缩性能进行了测试,并从理论上分析了其杨氏模量、弹性极限和屈服强度对温度的相依性.结果表明:该开孔泡沫材料在室温下表现出脆性泡沫材料变形断裂特征;在200℃以及更高温度下,该材料表现出塑性开孔泡沫材料变形特征,其应力-应变曲线分为3个阶段,即弹性阶段,平台阶段和压实阶段.开孔泡沫钛的杨氏模量、弹性极限和屈服强度随着温度的升高而减小,其对温度的相依性可分别表示为:E*=1.5217×109-5.988×105T,σ*ys=85.7-0.095T,σ*ys=99.1-0.16T 7.02×10-5T2.
Zhao Juan , Li Jianping , Guo Yongchun , Yang Zhong , Liang Minxian
2008, 37(2):281-285.
Abstract:用相图计算软件Pandat计算了Mg-Gd-Y合金的液相面投影图、室温(25℃)的等温截面图、Mg-xGd-2Y和Mg-xGd-7Y合金系的垂直截面图,并选取了Mg-5Gd-2Y和Mg-1Gd-7Y两种合金,通过相图计算与实验验证相结合的方法对合金的相平衡及凝固过程进行了研究.用光学显微镜、扫描电镜、能谱仪及示差扫描量热仪对该合金的室温平衡相组成及凝固过程的相变温度点进行了验证.结果表明,相平衡热力学计算结果与实验结果吻合,Mg-5Gd-2Y合金的凝固顺序为L-L α-Mg-α-Mg Mg5Gd-α-Mg Mg24Y5 Mg5Gd;Mg-1Gd-7Y合金的凝固顺序为L--L α-Mg-α-Mg Mg24Y5--α-Mg Mg24Y5 Mg5Gd,两合金的室温平衡组织均为α-Mg Mg24Y5 MgM5Gd.
Ma Guangbin , Zhu Zhenghou , Huang Yuhong , Xia Xiaoge , Li Tanghua
2008, 37(2):286-288.
Abstract:采用点压方式研究非晶FeCuNbSiB带材的压磁性能,利用X-Ray测试带材结构,用DSC确定相转变,用4294A阻抗分析仪测试阻抗.结果表明:非晶FeCuNbSiB带材具有优越的压磁性能和压磁稳定性,压磁敏感性可以通过调整退火工艺来实现.当退火温度为300℃,保温时间为1 h时非晶FeCuNbSiB带材的压磁性能最佳,在压力为1.42 MPa,频率为100MHz时,|△Z|可达2.88Ω.
Wang Qingfu , Liu Qinghe , Wang Xiaohong , Lang Dingmu , Li Kexue , Tang Kai , Liu Weihua
2008, 37(2):289-293.
Abstract:利用电化学测试技术、扫描电镜(SEM)及X射线能谱(EDS)对磁控溅射离子镀铌贫铀的电化学腐蚀行为进行了研究.实验结果表明:在50μg/g Cl-的KCl溶液中,铌的腐蚀电位远高于贫铀的腐蚀电位,铌镀层对贫铀是阴极性镀层,对贫铀的保护是基于其对腐蚀介质的物理屏障作用;镀铌贫铀的极化电阻和电化学阻抗幅值远大于贫铀,腐蚀电流远小于贫铀,铌镀层对贫铀具有良好的防腐蚀性能;镀铌贫铀的腐蚀特征为局部腐蚀,并由孔蚀向电偶腐蚀转变.
2008, 37(2):294-298.
Abstract:应用光学显微镜、扫描电镜(SEM)、X射线衍射(XRD)、透射电镜(TEM)以及磨粒磨损试验,研究了质量分数为0.8%的Y2O3对等离子熔覆钴基合金组织结构和耐磨性能的影响.结果表明:没有添加Y2O3的钴基合金熔覆层主要是由面心立方的γ(Co)和六方结构的M2C3构成,并且在钴基固溶体中存在着许多堆垛层错:0.8%Y2O3的加入,并未改变熔覆层的相组成,未熔的Y2O3存在,提高了位于钴基固溶体中堆垛层错的密度和宽度;此外,由于Y2O3的加入,熔覆层的凝固组织发生了变化,由柱状晶转变为等轴晶;稀土氧化物Y2O3作为异质形核核心,细化了组织,改善了熔覆层组织的择优分布,从而提高了熔覆层的耐磨性能.
Wang Guixiang , Li Ning , Dong Guojun
2008, 37(2):299-303.
Abstract:利用胶体钯活化后的铜电极在化学镀镍溶液中的混合电位-时间曲线来判断胶体钯活化液的活性,经催化活性好的胶体钯活化后的铜电极化学镀诱导时间短,而催化活性不好的诱导时间长.采用100 ml·L-1HCl解胶可将诱导时间缩短10 s.活化后铜电极在HClO4溶液中循环伏-安曲线也用来表征活化液的活性,活性好的活化液在HClO4溶液中析氢电位较正,析氢峰较明显,而活性差的反之.
Sun Weimin , Zhang Yi , Zheng Zhuo , Xu Dongnian , Liu Zheng , Dang Xinglong
2008, 37(2):304-307.
Abstract:用电弧放电法在H2 Ar混合气氛下同时制备了气相稳定和液相稳定的Cu纳米粉,并用Cu纳米粉配制了导电浆料.用XRD,TEM,DSC-TG,化学分析等手段研究了粉体的相结构、表面组成、形貌、粒度和氧化特性.结果表明:气相稳定和液相稳定的Cu纳米颗粒具有壳核结构,核为纳米Cu,壳分别为氧化层和松油醇(C10H18O)分子层;粉体的平均粒度分别为80 nm和70 nm;在空气中,包覆在Cu纳米粒子表面的松油醇分子在190℃左右基本脱附和分解;Cu纳米粉导电浆料在烧结温度180~200℃、保温时间60~70 min、真空度1.33 Pa条件下可获得电阻率为(2.12~5.82)×10-4Ω·cm的导电膜.
Cheng Gang , Yang Xiaoling , Xu Hui , Ni Jiansen , Zhou Bangxin
2008, 37(2):308-311.
Abstract:采用温压工艺制备了钕铁硼粘结磁体,研究了温压压力、温压温度、粘结剂种类及含量对磁体磁性能的影响,以及温压工艺对钕铁硼粘结磁体氧含量的影响.利用Nd2Fe14B/a-Fe系双相纳米晶磁粉为原料,在200℃下,采用12MPa的压力,获得性能最佳的磁体,其密度为6.43 g/cm3,磁性能为:Br=0.808 T,Hcb=461 kA/m,Hci=623 kA/m,(BH)max=101 kJ/m3.
Tang Yougen , Xie Zhenghe , Wan Weihua , Tang Renying
2008, 37(2):312-315.
Abstract:LaNiAl hydrogen storage alloys were prepared by arc melting method. The effects of annealing-treatment, Cu plating and SiO2 coating on the surfaces of annealing-treatment alloys were investigated. The results show the intensities of diffraction peaks increase after the alloy was annealed, revealing that the alloy was recrystalllzed and dendritic segregation was eliminated during the annealing process. the result that the surface compositions changed from the enrichment of La, Ni and Al to that of Si and O indicates that Si was coated on the powder surfaces in the form of SiO2. Electrochemical study indicates that the alloys treated show excellent performance. The discharge voltage increases and discharge curves become smooth. It is found that the annealed alloy coated with Cu shows the best performance with high discharge voltage and long discharge platform. The annealed alloy coated with SiO2 shows low discharge voltage, and longest discharge platform. The capacity losses of the alloys annealed, plating with Cu, and coated with SiO2 over 25 cycles are 7%, 4% and 5.5%, respectively. However, capacity loss of the alloys without modification is 21.8%.
Xin Guoqiang , Yang Xueqin , Dong Nan , Tian Xiubo , Yang Shiqin
2008, 37(2):316-319.
Abstract:采用PⅢ对Ti6Al4V合金进行表面处理,温度控制在300~400℃之间,利用小掠射角X射线衍射技术(GXRD)、扫描电镜(SEM)研究不同工艺条件下的相结构和表面形貌,并且测量处理后试样的显微硬度、摩擦磨损性能。结果表明:试样表面形成了金红石相,且试样表面变得粗糙;在390℃处理后的试样硬度提高27%,抗磨损性能提高。
Zhang Cuimei , Hui Xidong , Liu Xiongjun , Chen Guoliang
2008, 37(2):320-324.
Abstract:利用铜模铸造的方法制备了(Zr41.2Ti13.8Ni10Be22.5)1-x/87.5Cu12.5 x(x=1.6,6,11.2)块体非晶合金及其复相组织,分析了合金的相组成,热稳定性、力学性能及断口形貌.结果表明:随着铜含量的不断增多,尽管过冷液相区(ΔTx)逐渐增大,但非晶形成能力却不断下降.当合金的铜含量提高到18.5%时,非晶合金的压缩断裂强度达到2.2 Gpa,进一步增加铜含量到23.7%,压缩强度出现下降趋势.
Ma Li , Sun Yue , He Xiaodong
2008, 37(2):325-329.
Abstract:采用大功率电子束物理气相沉积(EB-PVD)技术制备了层厚比为1:1的Ti/Ti-Al微叠层复合材料薄板,用XRD和SEM对材料的微观结构进行了表征,对其室温及高温拉伸性能进行了测试.结果表明:材料由Ti,α2-Ti3Al和γ-TiAl相组成,层状结构对提高材料的室温塑性有利;尽管未经致密化处理的材料存在着较多微孔,但在金属间化合物层的反常强化及层间界面对裂纹的钝化作用下,材料仍具有较高的抗高温拉伸强度和良好的高温延迟断裂特性.
Yan Xiuwen , Qiu Tai , Li Liangfeng , Zhang Zhenzhong
2008, 37(2):330-333.
Abstract:利用直流电弧等离子体法成功制备了分散性较好的纳米链状Ag-Cu-In-Sn合金粉末.用X射线衍射(XRD)、透射电镜(TEM)和差示扫描量热分析(DSC)等手段对粉末的结构、粒度和热性能进行了表征.研究结果表明:通过优化工艺可制备粒度分布均匀,产率较高,平均粒度在45.03 nm的Ag-Cu-In-Sn合金粉末.该粉末具有独特的热性能,与微米合金粉末的熔点相比,其熔点下降了近160℃.
Xiu Weijie , Ying Pengzhan , Cui Jiaolin , Xue Haifeng
2008, 37(2):334-337.
Abstract:采用放电等离子烧结(SPS)方法制备Ag掺杂四元Ag-Bi-Se-Te合金,并分析研究其热电性能.结果表明:掺杂Ag后,合金AgxBi(2-x)Se0.3Te2.7(x=0.005~0.04)的Seebeck系数均为负值,说明材料属于n-型半导体;当温度大约在428.0K时,x=0.04合金的Seebeck系数绝对值(|a|)出现最大值,其值为1.80×10-4V·K-1,比三元合金Bi2Se0.3Te2.7的最大值增大约16%;材料电导率随Ag含量的增加而下降.如果采用相同方法制备且成分按(Bi2Te3)0.9-(Bi2-xAgxSe3)0.1(x=0~0.4)设计的材料热扩散系数进行估算,当温度在477.0 K时,合金AgxBi(2-x)Se0.3Te2.7(x=0.04)的ZT值出现最大值,其值为0.75,比典型三元合金Bi2Se0.3Te2.7的最大值增大约0.09.
Zhang Zhiwei , Chen Jingchao , Pan Yong , Zhou Xiaolong , Liu Fangfang , Zhang Kunhua , Guan Weiming
2008, 37(2):338-341.
Abstract:The Ag/SnO2 composites were prepared by reactive synthesis and the microstructure uniformity and performance variation of Ag/SnO2 composites in the severe plastic deformation were investigated. The SEM analysis shows that with increasing of true strain, the fiber like microstructure vanishes gradually, and the distribution of SnO2 particles changes from cluster like to uniform. The test results of electrical and mechanical performances as well as grain sizes indicate that the performances of the Ag/SnO2 composites by severe plastic deformation are improved greatly, their mass loss of the contacts via larger true strain extrusion decreases obviously.
2008, 37(2):342-345.
Abstract:采用复合镀技术在铜箔基体上沉积了K2Ti6O13晶须增强镍磷基化学复合镀层(Ni-P-PTWS).通过拉伸试验数据拟合得到了Ni-P-PTWs复合镀层的弹性模量与K2Ti6O13晶须体积分数的计算公式.用X射线衍射法分析了不同pH值和不同热处理温度下所得Ni-P-PTWs复合镀层的残余应力.结果表明,当镀液pH值为3.8时,镀层的本征应力为压应力,而当镀液pH值为4.4或5.2时,镀层的本征应力为拉应力.经过200℃,1 h热处理,镀层的本征应力减小;经过400℃,1 h或600℃,1h热处理,镀层的本征应力增大.
Zhang Hanzhuo , Jiang Zhonghao , Lian Jianshe
2008, 37(2):346-349.
Abstract:分别采用直流和脉冲电沉积工艺制各了两种纳米晶铜DC-Cu和PE-Cu,平均晶粒尺寸分别为65nm和33nm.室温单向拉伸试验表明,DC-Cu和PE-Cu的屈服强度分别为332 MPa和545 MPa,基本符合Hall-Petch经验公式;其断裂应变分别为18.2%和3.4%,与粗晶铜相比韧性大幅下降.随着应变速率的升高,两种纳米晶铜均表现出强度增大、韧性降低的规律.DC-Cu和PE-Cu的应变速率敏感系数分别为0.020和0.029,激活体积分别为90b3和36b3.分析认为,两种纳米晶铜的变形机制仍以位错模式为主.
Zhou Zeyuan , Yu Shuxiang , Jiang Yong , Ding Bingjun , Ni Longxing
2008, 37(2):350-353.
Abstract:采用Zn置换HAuCl4溶液的方法制备了具有不同形貌的纳米金,并研究了HAuCl4溶液的浓度对纳米金形貌的影响.实验结果表明,纳米金的形貌主要取决于HAuCl4溶液的浓度.当HAuCl4溶液的浓度为0.01 mmol/L时,置换反应进行5 min后的产物是金纳米颗粒,其粒径为10~50 nm,24 h后金颗粒的粒径超过100 nm,金颗粒团聚成金花状.当HAuCl4溶液的浓度为1 mmol/L时,金颗粒的粒径为数百纳米,部分金颗粒团聚成金花状.当HAuCl4溶液的浓度为10 mmol/L时,在金颗粒中出现由纳米金片组成的多晶枝晶,多晶枝晶随后通过OA和OR机制转变成单晶枝晶.当HAuCl4溶液的浓度为30 mmol/L时,反应时直接生成金枝晶.因此,通过控制HAuCl4溶液的浓度,可制备具有不同形貌的纳米金.
2008, 37(2):354-356.
Abstract:采用DSC技术研究了SIMA法制备半固态AZ91D镁合金坯料过程中形变率与共晶熔化激活能的关系.结果表明:形变AZ91D镁合金内部存在位错、孪晶缺陷,合金的共晶熔化激活能随变形率的增大而变小,当形变率达到40%时,共晶熔化激活能下降很少;共晶熔化开始温度随变形率的增大略有下降.
Xiao FengJuan , Chang Hong , Wu Xinli
2008, 37(2):357-361.
Abstract:利用酸碱刻蚀两步化学法对Ti进行活化处理,经水热电沉积制备Ti/羟基磷灰石涂层(HA),用SEM,XRD,FTIR和EDS对涂层进行分析和表征,用微控电子万能试验机对基体和涂层的界面结合强度进行测试,将涂层在牛血清白蛋白溶液(BSA)中浸泡2 h~3 d后,分析涂层与BSA溶液的FTIR和XSP光谱.结果表明:活化处理后的Ti表面形成了活性TiO2过渡层,活化过渡层使涂层与基体的结合强度显著提高;涂层形貌、元素比例与骨组织纤维相一致.涂层与BSA作用后的FTIR光谱表明,在涂层中引入了BSA酰胺带基团,在BSA溶液中又出现HA中PO43-基团,蛋白质酰胺Ⅰ带、酰胺Ⅱ带和HA中PO43-的红外光谱的位置和谱峰均发生变化,由此推测了Ti/HA涂层与BSA间的作用机制,指出:正是由于Ti/HA涂层与BSA间的相互作用使涂层得以在蛋白质结构中交互有序地排列生长,这是Ti/HA涂层具有生物相容性的基础.
Yao Sujuan , Yi Danqing , Liang Dongmei , Li Wangxing
2008, 37(2):362-365.
Abstract:The microstructure and corrosion resistant property of AZ91 magnesium alloy with different additions of Sc were investigated The microstructures were observed by OM and SEM, and the corrosion properties were studied by electrochemical technique. The results show that with the increase of Sc content in the range from 0.18%-0.57%, the alloy microstructures are fined continuously, and the corrosion resistance of the alloy is improved. Although the change of the corrosion voltage is not big, the corrosion current density increases obviously. When Sc content is 0.39%, the minimum current density appears.
Kang Jinxing , Zhao Wenzhen , Xu Yingge , Sun Liming
2008, 37(2):366-369.
Abstract:采用直流电沉积方法,通过改变特殊添加剂C7H4NO3SNa·2H2O浓度、沉积液温度、电流密度,制备出不同厚度的纳米晶镍覆层材料,利用高分辨透射电子显微镜(HRTEM)对沉积覆层材料的组织结构进行分析,从理论上推导了电流效率的计算公式,对不同工艺条件下电流效率的变化规律进行了研究.结果表明:电沉积纳米晶镍的电流效率可按ηMk=2.4403×105v/ik计算得出;电沉积纳米晶镍的电流效率随着添加剂C7H4NO3SNa·2H2O浓度的增加而下降;随着电流密度和温度的增加先增加后下降,在温度60℃左右时最大.
Zhang Linli , Ling Yawen , Zhang Ling , Shi Peng
2008, 37(2):370-373.
Abstract:用固相反应法制备ZnO:Eu3 纳米粉末,研究其发光特性.观察到从基质ZnO到Eu3 的能量传递现象.研究表明,不论是ZnO基质的激子激发还是Eu3 的高能态激发,随着Eu3 浓度从0.1 mol%增加到1 mol%,Eu3 的发射增强.在基质激子的激发下,ZnO:Eu3 纳米粉末产生了很强的Eu3 红色特征发射而没有ZnO的宽带发光.结果表明,ZnO:Eu3 纳米粉末的XRD谱中不存在可观测到的Eu2O3杂相,激发光谱中出现ZnO的带间激发与纯Eu2O3的激发光谱不同,这几方面说明了Eu3 进入了ZnO的晶格中.
Zhou Xiaoxiao , Cheng Yungui , Yan Yigang , Liang Hao , Wu Chaoling , Tao Mingda
2008, 37(2):374-376.
Abstract:Fe的添加,提高了金属钒的活化性能和放氢平台压力,降低吸放氢容量.Fe含量<1%(原子分数,下同),对二氢化物并无明显影响,Fe含量>1%,二氢化物平台压明显升高,容量明显下降,氢化物的生成焓明显降低;Fe的添加对一氢化物并无明显的影响.随着Fe含量的增加,合金的晶格常数和晶胞体积呈线性趋势降低.
Total visitors:
Address:96 weiyanglu, xi'an,Shaanxi, P.R.China Postcode:710016 ServiceTel:0086-26-86231117
E-mail:rmme@c-nin.com
Copyright:Rare Metal Materials and Engineering ® 2024 All Rights Reserved Support:Beijing E-Tiller Technology Development Co., Ltd. ICP: