制备方式对MoRe合金组织性能的影响

通过粉冶和熔炼2种制备方式分别制取了Φ3 mm、Φ0.1 mm的丝及0.03 mm×0.3 mm×1 mm的窄带,对不同加工阶段的样品进行了金相观察、扫描电镜分析、及拉伸性能、弹性模量测试等.比较了2种制备方式的显微组织和力学性能,为工程应用选材提供了依据.     

高能喷丸表面纳米化对工业纯钛组织性能的影响

用高能振动喷丸法对工业纯钛进行了表面纳米化的研究。用X 射线衍射、光镜和透射电镜对表层变形层金相组织、晶粒尺寸、显微硬度进行分析。结果表明 ,具有密排六方晶体结构的工业纯钛经高能喷丸处理后 ,在表面可以形成具有一定厚度的纳米晶粒组织 ;随着高能喷丸时间的增加 ,表面层的晶粒尺寸变小 ,而表面硬度提高。     

Catalytic activity of Au/Fe-PILC and Au/Fe-oxide catalysts for catalytic combustion of formaldehyde

Iron polymeric hydroxygroups pillared clays （Fe-PILC） were prepared by Na^＋-montmorillonite with iron pillaring agent. 2.01Au/Fe-PILC catalyst was obtained by deposited-precipitation （DP） method. 2.52Au/Fe-oxide catalyst was prepared by co-precipitation method. The catalytic activity of these catalysts was measured by catalytic combustion of formaldehyde. The catalyst of 2.01Au/Fe-PILC exhibits the high catalytic activity. The catalytic combustion reaction of formaldehyde proceeds at considerable rates at 20 ℃ and complete burn-off of formaldehyde is achieved at 120 ℃. The structure of catalysts, the valence state of gold and the size of gold particles were investigated by means of X-ray powder diffractometry, X-ray photoelectron spectroscopy and transmission electron microscopy. The results show that gold atoms with partially positive charge exist in the catalyst and play an important role in the catalytic activity. In addition, nano-sized, well-dispersed gold particles and good adsorption properties of support are necessary to obtain high activity Au catalysts for catalytic combustion of formaldehyde.     

弛豫铁电体Pb(Mg1/3Nb2/3)O3-PbTiO3的相变

测量了(1-x％)镁铌酸铅-x％钛酸铅(1≤X≤11)(简称PMNTx)陶瓷样品的介电常数、内耗和Young’s模量．观测到在Tm温度附近，即在介电常数达到最大值时，出现一个内耗峰，并且模量发生软化．这反映了极化纳米微畴的弛豫．对于PMNTx(5≤x≤11)的样品，在Tm温度以下的某个温度出现附加的内耗峰和Young’s模量的异常，表明样品中发生了自发的弛豫铁电到铁电(简称R-F)的相变，对R-F相变的机制进行了讨论．     

在工业中采用钛合金的微弧氧化

采用硬度测试，金相显微观察和透射电镜分析等方法，研究了微量稀土Er对高纯铝再结晶行为的影响，结果表明，弥散分布的细小Al3Er质点对位错和亚晶界具有钉扎作用，可以有效抑制再结晶，将高纯铝的再结晶温度提高50左右，同时还能显著细化再结晶晶粒，再结晶形核机制是亚晶聚合和亚昌长大双重机制。     

改善银首饰铸造质量的措施

斯特林银首饰铸造时经常会出现气孔、缩孔、砂眼、氧化物夹杂等,其原因主要来自2个方面,一是在铸造过程中各工序的操作不当,尤其是水线的设置、开粉操作、焙烧制度等关键工序,必须加强操作过程的控制;二是与银本身的性质有关,银在凝固时氧的溶解度骤减,气体容易析出导致气孔;斯特林银主要以铜作为合金化元素,容易氧化形成夹杂。在熔炼或铸造过程中要尽量避免金属液接触大气,采用真空、或使用惰性气体、还原性火焰、硼酸等进行保护,可以减少铸造缺陷的发生。     

Effects of ZrO2 on the structure and magnetic properties of CoPt thin films

[CoPt 1.5 ml/ZrO2 xnm]10 multilayer films were deposited on glass substrates by magnetron sputtering and then annealed in vacuum at 600℃ for 30 min. Their structures and magnetic properties were investigated as a function of ZrO2 content. The results show that the grain size and coercivity first increase and then decrease with the increase in ZrO2 content. The maximum coercivity and grain size are obtained at 37 vol.% of ZrO2. The content of ZrO2 in the film plays an important role in the separation of CoPt grains and in the reduction of intergrain exchange interaction. On the basis of the studies of angular dependent coercivity, it is found that the magnetization reversal of CoPt films with （111 ） texture is different from either the domain wall motion or the S-W type of rotation mode.     

High-rate capability of spinel LiNi0.05Mn1.95O4 cathode for Li-ion batteries prepared via coprecipitated precursor

Spinel LiNi0.05Mn1.95O4 cathode material for lithium ion batteries was synthesized by solid-state reaction from coprecipitated Ni-Mn hydroxide precursors and characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and galvanostatic charge-discharge tests. It is found that LiNi0.05Mn1.95O4 powder has an ordered cubic spinel phase （space group Fd3m） and exhibits superior rate capability. After 450 cycles, the LiNi0.05Mn1.95O4/carbonaceous mesophase spheres（CMS） Li-ion batteries can retain 96.0% and 93.3% capacity at 5C and 10C charge/discharge rate, respectively, compared with 85.3% （5C） and 80.5% （10C） retention for LiMn204 batteries. However, the initial discharge capacity of LiNi0.05Mn1.95O4/CMS batteries at 1C charge/discharge rate （96.20 mA.h/g） is slightly lower than that of the LiMn2O4 batteries （100.98 mA.h/g） due to the increased average oxidation state of Mn inLiNi0.05Mn1.95O4.     

电磁无接触成形过程熔体形状的数值模拟及实验研究

应用有限元方法模拟计算了电磁约束成形过程中感应器结构、固／液界面位置、熔体上顶面位置、电流频率及熔体种类对熔体形状的作用规律。结果表明：喇叭形内壁的感应器中熔体可获得侧面基本垂直的理想形状；固／液界面、熔体上顶面位置对熔体形状有明显的影响：电流频率的变化对熔体成形形状的影响很小：在感应器结构、固／液界面及熔体上顶面位置等确定后，合金种类对熔体形状几乎没有影响。同时对电磁成形规律进行了研究，表明实验与模拟计算的结果取得了很好的吻合。用电磁成形方法完成了Al合金、TiAl化合物和Ni基高温合金的无接触成形，制备出了样件，并对组织实现了定向控制。     

三维圆柱直齿轮的参数化设计

研究了采用Visual LISP语言编制程序绘制三维圆柱直齿轮的方法。用Visual LISP语言编制程序进行二次开发，为AutoCAD新增了三维圆柱直齿轮绘图命令，使得在机械产品三维CAD设计时，绘制三维直齿轮更为方便，提高三维设计的绘图工作效率。