Nb含量对Zr55Cu30Ni5Al10块体金属玻璃热稳定性和力学性能的影响

在水冷铜坩埚中采用铜模吸铸法制备出直径Ф3 mm的(Zr0.55Al0.10Ni0.05Cu0.30)100-xNbx(x=0,2,4,6,8,10)合金试样,利用X射线衍射(XRD)、差热分析(DSC)、扫描电镜(SEM)以及准静态压缩试验方法研究了Nb含量对Zr55Cu30Ni5Al10块体金属玻璃的非晶形成能力、热稳定性、力学性能和组织的影响。研究结果表明,添加适量的Nb元素能提高Zr55Cu30Ni5Al10合金的热稳定性和非晶形成能力。当Nb含量为x=8时,合金具有最宽的过冷液相区(ΔTx=86 K)和最大的非晶形成能力(参数γ=Tx/(Tg+Tl)=0.416)。对于Zr55Cu30Ni5Al10合金,优化Nb元素掺杂量可以获得最佳的非晶形成能力和热稳定性。Nb的适量添加也有利于提高Zr55Cu30Ni5Al10块体金属玻璃的压缩断裂强度和塑性变形能力,其中x=8时,合金的压缩断裂强度和塑性应变量分别达到1877MPa和1.92%,并具有加工硬化现象。     

Y基非晶合金的形成及晶化动力学

利用单辊急冷法制备Y56-xZrxA124Co20(x=0,5,10)非晶合金,研究Zr含量对该非晶合金的形成能力及热稳定性的影响.研究结果表明,添加元素Zr可以提高Y56A124Co20合金的非晶形成能力和热稳定性,而且随着Zr含量增加,合金的非晶形成能力提高.通过示差扫描量热法(DSC)研究了Y56A124Co20和Y46Zr10A124Co20的晶化动力学,前者的玻璃转变激活能和晶化激活能分别为366.5 KJ/mol和259.7 KJ/mol,后者的玻璃转变激活能和晶化激活能分别为415.6 KJ/mol和319.5KJ/mol,从理论上说明添加元素Zr可以改善Y56A124Co20合金的非晶形成能力和热稳定性.     

低纯材料制备Cu-Zr基非晶合金

Cu-Zr基非晶合金的玻璃形成能力与原材料中的氧和其他非金属杂质非常敏感。采用低纯材料通过铜模吸铸法制备Cu45Zr47Al8非晶合金,研究杂质对Cu-Zr基非晶合金玻璃形成能力和热稳定性的影响。用X射线衍射(XRD),透射电子显微镜(TEM)和能谱仪(EDS)分析合金组织结构及差示扫描量热法(DSC)分析合金的热稳定性。实验结果表明:低纯材料制备出临界直径7 mm以上的非晶合金。由于低纯材料中的一些微量杂质元素被认为合金化元素,适量的杂质元素没有导致合金的玻璃形成能力降低;而过量的氧和其他杂质元素导致非均匀形核并随之发生结晶,合金的玻璃形成能力明显地降低。低纯材料制备的合金的ΔTx和晶化激活能均高于高纯原料制备的;并基于Kissinger方法所构建的开始晶化曲线表明低纯材料制备的合金的晶化孕育期更长,说明低纯材料制备的合金具有更强的热稳定性。低纯材料成功制备出大块Cu-Zr基非晶合金,为促进非晶合金的商业应用有重要意义。     

微量元素Y、Ag对Cu基非晶合金玻璃形成能力的影响

采用单辊旋淬法制备了Cu50Zr42Al8,Cu46 Zr47-xAl7Yx(x=2,5),Cu43Zr42AlsAg7和Cu43Zr42Al8Ag5 Y2非晶合金薄带,利用X射线衍射和差示扫描量热分析研究了合金样品的玻璃形成能力和热稳定性.结果表明,在Cu50Zr42Al8中添加适量的Ag、Y后使得非晶合金的短程有序结构发生改变.合金Cu46Zr47-xAl7Yx(x=2,5)的过冷液相区宽度ΔTx分别比Cu50 Zr42 Al8增加了19K、30K,约化玻璃转变温度Trg从0.565分别增加到0.579和0.566,参数γ从0.402分别增加到0.418和0.420,说明Y的添加提高了非晶合金的热稳定性和玻璃形成能力.合金Cu43Zr42 Al8Ag7和Cu43Zr42Al8Ag5Y2与Cu50Zr42Al8相比,约化玻璃转变温度Trg及参数γ均有了明显的提高,达到了0.619、0.416和0.609、0.411,表明Ag的添加、Ag和Y的同时添加均提高了Cu - Zr -Al系非晶合金的玻璃形成能力,但Ag的效果更加显著.     

半固态处理对(Cu_(0.7)Fe_(0.3))_(88-x)Al_(12)Zr_x非晶复合材料组织和力学性能的影响

对Cu-Fe非晶合金基复合材料进行了成分设计,研究了半固态处理工艺对(Cu0.7Fe0.3)88-xAl12Zrx组织和力学性能的影响。结果表明,Zr含量增加能够提高(Cu0.7Fe0.3)88-xAl12Zrx的非晶形成能力,x=50时试样为全非晶结构,过热吸铸试样其过冷液相区宽度ΔTx为92.4 K,约化玻璃转变温度Trg和γ参数分别为0.415和0.361,试样具有良好的热稳定性和非晶形成能力,且其断裂强度显著高于复合材料,压缩断裂强度高达1734 MPa。x=10的试样中马氏体相对塑性的提高有一定效果,但是缺乏非晶基体的强度。随着Zr的添加,Fe的比例降低,试样中塑性相消失,析出脆性金属间化合物较多,试样脆性大。半固态处理试样的非晶热稳定性降低,有利于晶体相的析出,且母合金经半固态处理过后试样的组织更加均匀,力学性能得到明显改善。     

冷却速度对Cu_(46)Zr_(44)Al_5Nb_5块体非晶合金组织和力学性能的影响

通过磁悬浮熔炼-水冷铜模吸铸法制备了Cu46Zr44Al5Nb5块体非晶合金阶梯形试样,由X射线衍射(XRD),差示扫描量热仪(DSC)和万能试验机分别表征试样的结构、热力学和力学行为,研究其组织、热稳定性和力学性能与冷却速率的关系。结果表明,Cu46Zr44Al5Nb5合金具有较强的非晶形成能力和良好的热稳定性,其热力学行为表现出尺寸效应。熔体凝固冷却速率对试样尺寸变化敏感,随着试样尺寸的增加,冷却速度呈倍数递减、合金结构的无序度下降,原子排列向稳态转变,导致非晶合金的热稳定性降低。合金的玻璃转变温度不是定值,而是随冷却速度增加而升高,过冷液相区宽度ΔTx、约化玻璃转变温度Trg和晶化放热ΔH随直径的增加而降低,玻璃转变温度向低温漂移。随着直径的增加,冷却速度的降低,非晶合金的短程有序范围增大,最近邻原子间距减小,非晶合金结构的无序密堆性下降,原子排列向稳态转变,导致抗压强度降低,合金的断裂强度随试样直径的增大而减小。     

Ti对Cu基块体非晶合金的玻璃转变动力学影响

本文选用非晶形成能力高,且在玻璃转变区和过冷液相区有高热稳定性的Cu46Zr47-xAl7Tix(x=0,1.5)块体非晶合金为研究对象。利用X射线衍射分析和差示扫描量热分析(DSC),研究了Ti元素的添加对于Cu基非晶合金玻璃转变动力学的影响。研究结果表明,在Cu46Zr47Al7块体非晶合金中用1.5%的Ti替代Zr之后,利用VFT方程分析得知合金的强度指数D由2.54增大到3.78,脆性指数m也从39减小到34,表现出了更高的玻璃形成能力。     

熔体过热度对Zr基非晶合金力学性能和热稳定性能的影响

采用吸铸法制备Zr70Cu13.5Ni8.5Al8非晶合金,采用同步差示扫描量热仪(DSC)和万能试验机对非晶合金显微结构进行表征和力学性能测试,并利用XRD和SEM对试样的相组成和的剪切带观察。研究发现：随着吸铸功率增加,热稳定性、玻璃形成能力不断提高;Zr70Cu13.5Ni8.5Al8非晶合金的锯齿流变现象越明显,综合力学性能越好,其中吸铸功率8 kW时,试样的屈服强度、抗压强度和塑性达到最值,室温综合力学性能最好,且剪切带分布情况最好,但是继续提高吸铸功率,力学性能反而变差。     

Zr对Y56Al24Co20非晶形成能力和热稳定性的影响

以Y56Al24Co20非晶合金为基础合金系,用廉价Zr替代部分高价Y,通过单辊急冷法成功地制备出Y56-x-ZrxAl24Co20(x=5,10,15)非晶合金;通过X射线衍射(XRD)和差示扫描量热法(DSC)研究其非晶形成能力和热稳定性.结果表明,随Zr含量增加,合金的非晶形成能力提高,但当Zr含量超过10%(摩尔分数)时,其非晶形成能力反而降低;Y46Zr10Al24Co20具有最大的非晶形成能力和良好的热稳定性.以上结果均从组元个数、原子半径、混合热和电负性的角度进行了实验论证.     

锆基大块非晶合金的非等温晶化动力学效应

采用非等温差示扫描量热法(DSC)研究了锆基非晶合金Zr60Al15Ni25、Zr65Al10Ni10Cu15的晶化动力学.结果显示,随着升温速率的加快,这两种非晶合金的特征温度Tg、Tx、Tp均向高温区移动,且过冷液相区逐渐加宽,表明非晶合金的玻璃化转变和晶化均具有动力学效应.分别采用Kissinger法和Ozawa法计算各非晶合金的激活能,两种方法的计算结果相近.从激活能数据得出,两种锆基非晶合金的热稳定性均较强;与非晶合金Zr60Al15Ni25相比,Zr65Al10Ni10Cu15虽较难形成玻璃化转变和开始晶化,但其晶化一旦开始则随后的过程反而更容易进行.     

Studies on the Preparation and Properties of AIF_3－based Rare Earth Fluoride Glass

ＳｔｕｄｉｅｓｏｎｔｈｅＰｒｅｐａｒａｔｉｏｎａｎｄＰｒｏｐｅｒｔｉｅｓｏｆＡＩＦ_３－ｂａｓｅｄＲａｒｅＥａｒｔｈＦｌｕｏｒｉｄｅＧｌａｓｓ￥ＪｉａｎｇＫａｉ（蒋凯），ＹａｎｇＬｉｎ（杨林），ＬｉＷｕｊｕ（李五聚）（ＨｅｎａｎＮｏｒｍａｌＵｎｉｖｅ?..     

Review on Application of Rare Earth Polishing Powders in Glass Polishing

The paper reviewed different explanations to the mechanism of glass polishing, the practices of glass polishing and the preparation of polishing powders, addressed the growth mechanism of CeO2 crystals, summarized the roles of rare earth elements in glass polishing and the factors that may influence the polishing effects, and specified the existing problems in glass polishing.     

NMR Study on Structural Characteristics of Rare Earth Doped Boro-Alumino- Silicate Glasses

The structural characteristics of Re2O3 doped B2O3-Al2O3-SiO2 glasses and factors such as the component and heat-treating conditions affecting the glass structure were investigated by magic angle spin nuclear magnetic resonance （MAS NMR） spectroscopy and differential thermal analysis （DTA）. It is found that, in B2O3-Al2O3-SiO2 glass, the boron （4）, and Al（5）, Al（6） changes to Al（4）. On the other hand, compared with Ba^2＋ , RE^3＋ can accumulate the boron network because of its higher field strength, which results in a large network structure. With the increase of samarium oxide, the silicate coordination Qa（3T） will have predominance gradually. Heat-treatment has little effect on the boron and aluminum coordination sites in the glass structure.     

Fabrication and gain performance of Er^3＋/Yb^3＋-codoped tellurite glass fiber

Er^3＋/Yb^3＋-codoped TeO2-ZnO-BaO-La2O3 tellurite glass fiber was fabricated by rotation and rod-in-tube technologies. The thermal stability and optical refractive index of the core and cladding glasses were determined by DTA and optical coupler, respectively. The average background loss of tellurite glass fiber was 1.8 dB/m at 1310 nm. Optical microscopy and field emission scanning electron microscope （FESEM） were used to study structural characteristics of preforms and optical fibers. The main loss of tellurite glass fiber could be attributed to scatter centre due to core-cladding interface defects. The amplifier performance of tellurite glass fiber was investigated by pumping with 980 nm laser diode （LD）. The gain coefficient and maximum signal gain were 0.21 dB/mW and 10 dB, respectively, for a pumping power of 120 mW. Gains exceeding 5 dB were obtained over 30 nm bandwidth from 1535 to 1565 nm. The minimum noise figure was 4.8 dB at 1557 nm.     

高性能铝门窗的发展前景

本文回顾了我国铝门窗的发展历程,分析了目前我国铝门窗的现状,论述了高性能铝门窗的特点及在我国的发展趋势。     

Fabrication and gain performance of Er3+/Yb3+-codoped tellurite glass fiber

Er3+/Yb3+-codoped TeO2-ZnO-BaO-La2O3 tellurite glass fiber was fabricated by rotation and rod-in-tube technologies. The ther-mal stability and optical refractive index of the core and cladding glasses were determined by DTA and optical coupler, respectively. The av-erage background loss of tellurite glass fiber was 1.8 dB/m at 1310 nm. Optical microscopy and field emission scanning electron microscope (FESEM) were used to study structural characteristics of preforms and optical fibers. The main loss of tellurite glass fiber could be attributed to scatter centre due to core-cladding interface defects. The amplifier performance of tellurite glass fiber was investigated by pumping with 980 nm laser diode (LD). The gain coefficient and maximum signal gain were 0.21 dB/mW and 10 dB, respectively, for a pumping power of 120 mW. Gains exceeding 5 dB were obtained over 30 um bandwidth from 1535 to 1565 nm. The minimum noise figure was 4.8 dB at 1557 um.     

Preparation and Spectra Properties of BaO-Al2O3-P2O5-Sm2O3 System Protection Glasses

The forming-regions of phosphate glasses doped with high Sm2O3 contents were studied by two step melting method. The relationship between absorption spectrum and rare earth contents was also discussed. The spectra of BASP glasses were measured by spectrophotometer. The results show that the forming regions will shrink with the increase of Al2O3 and it is difficult to form glass when [PO4]/[AlO4]＜2. The forming regions tend to be a closed elliptical, and the intensity of characteristic absorption peak increases gradually with the increase of Sm2O3, the absorption lines broadens non-uniformly and there is approximate linear relation between optical density at the 1064 nm wavelength and Sm2O3 content.     

我国玻璃炉窑的现状及其节能技术的发展

玻璃熔窑是高能耗的热工设备，它占玻璃工厂总能耗的70％～80％，玻璃工业要想最大限度的节约能源，提高熔窑的能源利用率是一条有效的途径。本文主要介绍了我国玻璃工业的现状以及节能技术在玻璃熔窑上的应用。     

Effect of Aluminium Addition on Glass Forming Ability of Nd55-x Al10＋x Fe15 Co20 （x = 0, 5, 10） Alloys

Nd55-x Al10＋x Fe15 （x =0, 5, 10） bulk glass-forming alloys with distinct glass transition in differential scanning calorimetry （DSC） traces were obtained by suction casting, The glass forming ability （GFA） of the alloys was investigated. It was found that the reduced glass transition temperature （Trg） and the parameter γ of the alloys increased with the increasing concentration of Al. The glass formation enthalpy of the alloys was calculated based on Miedema＇s model, and it was suggested that the GFA of the alloys could be enhanced by the decrease of the glass formation enthalpy with Al additions.     

Kinetics of Glass Transition and Crystallization in Carbon Nanotube Reinforced Mg-Cu-Gd Bulk Metallic Glass

Mg65Cu25Gd10 bulk metallic glass and its carbon nanotube reinforced composite were prepared. Differential scanning calorimeter （DSC） was used to investigate the kinetics of glass transition and crystallization processes. The influence of CNTs addition to the glass matrix on the glass transition and crystallization kinetics was studied. It is shown that the kinetic effect on glass transition and crystallization are preserved for both the monothetic glass and its glass composite. Adding CNTs in to the glass matrix reduces the influence of the heating rate on the crystallization process. In addition, the CNTs increase the energetic barrier for the glass transition. This results in the decrease of GFA. The mechanism of the GFA decrease was also discussed.