金属硅的氧化精炼

冶金硅是生产有机硅和电子用硅的重要原材料 ,需精炼处理以降低其中的杂质。氧化法是比较有效的精炼除杂法 ,利用该法时选择具有合适密度、粘度、液相线温度和界面张力的炉渣是保证精炼反应顺利进行的关键。以钠钙硅酸盐玻璃为氧化剂对冶金硅的脱铝和脱钙进行了试验。结果表明冶金硅中的杂质铝钙去除率最高可达 93.1%和 96 .4%,铝和钙的含量最低降至 0 .0 7%和 0 .0 2 5 %,达到了很好的精炼效果。     

Ca对Mg-9％Al合金表面张力的影响

通过添加Ca镁合金可以提高阻燃性能,研究了Ca加入量和温度对Mg-9％Al合金表面张力的影响.结果表明:在相同温度下,随着Ca加入量的增加Mg-9％A1合金熔体的表面张力减小,且呈指数趋势降低;同种成分的镁合金熔体的表面张力随温度升高而降低,在760℃以下时液态金属表面张力随温度的升高呈线性降低,在760℃以上液态金属表面张力呈指数降低.同时,加入Ca后Mg-9％Al合金晶粒得到细化.     

BPSG膜的CVD方法

一种用于在半导体晶片或者衬底上原位形成高浓度硼磷硅酸盐玻璃膜的方法和装置。在实施例中，该方法由将衬底提供到腔室中开始。该方法通过将硅源、氧源、硼源和磷源提供到腔室中以便在衬底上形成高浓度硼磷硅酸盐玻璃层继续。该方法进一步包括回流形成在衬底上的高浓度硼磷硅酸盐玻璃层。     

冶金硅渣烧结多孔微晶玻璃的结构及性能

以冶金硅渣为主要原料,采用水淬粉体直接烧结工艺,制备多孔微晶玻璃。利用XRD、DTA/TG、SEM以及图像分析等技术,研究烧结工艺对多孔微晶玻璃气孔孔径、表观密度、晶相组成以及抗压强度的影响。结果表明:多孔微晶玻璃的气孔孔径随烧结温度升高以及烧结时间延长而增大,随升温速率的增大先增大后减小;表观密度随烧结时间延长逐渐增大,随烧结温度升高和升温速率增大呈现出先减小后增大的趋势;抗压强度随烧结温度升高先缓慢增大后急剧降低。多孔微晶玻璃最佳烧结工艺是以30℃/min的升温速率加热到800℃烧结30 min,此时多孔微晶玻璃的平均孔径为1.2 mm,表观密度为0.81 g/cm~3,抗压强度为4.6 MPa。     

铝硼硅玻璃基体中金刚石氧化机理

开展金刚石/铝硼硅玻璃复合材料的烧结试验,通过TG-DSC分析、XRD分析和Raman分析,研究铝硼硅玻璃熔体中金刚石的氧化反应机理。试验结果表明:烧结纯铝硼硅玻璃时,在1000 ℃以下,没有任何化学反应发生;烧结金刚石/铝硼硅玻璃复合材料时,温度高于814 °C后会发生体积膨胀、强度降低的现象;烧结温度780 ℃为最理想烧结温度,复合材料膨胀率约10%,抗折强度约39.0 MPa。在烧结温度不超过908.4 ℃时,金刚石和游离氧而非铝硼硅玻璃中的氧化物之间发生了氧化反应。      

钠硼硅酸玻璃与铝的阳极焊工艺及结合机理

研究了钠硼硅酸玻璃与铝的阳极焊工艺, 分析了工艺参数对焊接过程的影响, 指出减小或消除由于两者热膨胀系数不匹配而产生的影响是焊接的关键, 焊合率及焊接电流受焊接温度与电压的影响. 同时对其结合机理进行了进一步的探讨, 发现玻璃与铝在阳极焊过程中形成以硅, 铝, 氧, 钠, 锌复合物为主的过渡层.     

电子束毛化对硼硅玻璃在可伐合金表面润湿性的影响

增加实际紧密接触面积能提高玻璃在金属表面的润湿性,文中提出了一种将可伐合金表面进行电子束毛化的方法来提高表面粗糙度. 采用座滴法研究了硼硅玻璃在毛化后可伐合金表面的润湿性. 结果表明,电子束毛化可以增大可伐合金表面的有效接触面积,促进熔融玻璃的润湿铺展,润湿角随着加热温度的升高和保温时间的延长而逐渐减小. 硼硅玻璃和氧化层之间的主要反应产物为Fe₂SiO₄,金属表面的高能束毛化和预氧化处理有效促进了玻璃-金属的机械-化学结合,有利于提高玻璃与金属的连接强度.     

钢化对钠钙硅玻璃弹性性能的影响

对钠钙硅玻璃在物理钢化和化学钢化前后的动态弹性模量、剪切模量、泊松比进行了研究.利用脉冲激励法测试玻璃的弹性性能,分析了2种钢化工艺对玻璃弹性性能的影响.讨论了钢化对玻璃力学性能变化的影响机理.试验结果表明,玻璃的弹性模量与其钢化后有较为明显的差别,物理钢化使其弹性模量比原片玻璃略有降低(约4%),而化学钢化玻璃使其弹性模量较原片玻璃有所提高(约6%),这一奇怪的现象是由于物理钢化过程中玻璃冷却后,内部的收缩要大于表面的收缩变形,从而使玻璃表层致密度降低,而化学钢化过程中采用离子交互方式,让较大的离子取代玻璃表层上较小的离子,使其表层致密度增加.     

玻璃加工用的金刚石磨具

金刚石磨具广泛地应用于玻璃加工行业。不论是铅玻璃、钠钙玻璃、硼硅玻璃还是石英玻璃和玻璃-陶瓷之类的特种玻璃,只有用金刚石磨具磨削加工才能获得既经济而工件又不崩边的效果。近年来,金刚石磨具制造商们研究了结合剂特性与金刚石磨料的匹配关系,以求适应几乎所有的加工用途。如今,经过改良的机床辅之以用最佳品级的金刚石与结合剂制成的磨具可应用于玻璃加工。     

工业硅造渣提纯中硅与渣的熔分研究

为了实现工业硅造渣除杂过程中硅与渣料在炉内高温状态下的分开排放,选用特制除硼渣料及冶金级硅粉在高温电阻炉中进行了硅与渣的熔分研究.考察了熔化温度、保温时间、硅液出炉温度、炉内气氛以及内衬材料对硅与渣分离的影响.结果发现:在高于硅和渣熔点较多的温度下,两者可依靠密度差及不同的表面张力实现一定程度的分离;延长保温时间有利于硅液中杂质的去除及硅和渣的充分分离；出炉温度较低,有利于硅液在凝固过程中杂质的富集;炉内应处于还原或惰性气体状态以避免硅的氧化;炉内坩埚材料应为石英质,以防止坩埚与硅发生反应.     

The effect of melt infiltration of borosilicate glass on biaxial flexural strength of porcelain-veneered zirconia

To evaluate the effect of melt infiltration on the biaxial flexural strength of porcelain-bonded zirconia, borosilicate glasses were used in this study. Presintered yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) blocks were milled and used for disc specimens. Prior to veneering of porcelain, the infiltration of borosilicate glass on zirconia was performed at 1,100 °C for 1 h. After a biaxial flexural test with the crosshead speed of 0.1 mm/min, fractured surfaces and interfaces between zirconia and veneer porcelain were observed with a Scanning Electron Microscope (SEM). The fracture strength of sintered zirconia and veneer porcelain was significantly increased by the melt infiltration of borosilicate glass (P < 0.05). The melt infiltration process of borosilicate glass greatly improved the Weibull modulus of sintered zirconia. However, the Weibull modulus of porcelain increased slightly. The sintered zirconia group showed a smooth fracture surface containing many pores, but the glass-infiltrated zirconia group showed a rough fracture surface.     

Effect of copper addition on the thermal contraction of indium melt clusters

The structure of In-1%Cu and In-5%Cu (mass fraction) alloy melts were studied at different temperatures above liquidus by using a high-temperature X-ray diffractometer and were compared with that of pure In melt. Experimental results show that with the addition of 1% Cu or 5% Cu, the thermal contraction phenomenon of atom clusters occurs in melts with the temperature increasing like pure In melt. With the addition of 1% Cu, the thermal contraction of atom clusters increases and the contraction is not homogeneous in the whole measurement temperature range. The sudden change and noticeable contraction can be found in the range of 280-390℃. The temperature range of the sudden change is lower than that of pure In melt. With the addition of 5% Cu, the thermal contraction of atom clusters decreases and the contraction is not consistent in the whole measurement temperature range. The anomalous change can be measured at about 600 ℃. At the same superheating temperature, the nearest interatomic distance r1 of     

Ge–Al and Sn–Al alloys capillary properties in contact with aluminum nitride

Experimental isotherms are presented for (1) wettability of AlN ceramics by Ge–Al and Sn–Al alloys, (2) surface tension and density of Ge–Al and Sn–Al alloys in the whole concentration range. Complex consideration of capillary characteristics of the melts under study is performed taking into account data available on thermodynamic activities of the melt components. The contact angle isotherms pass the minimum point for both systems. The contact angle value drops with Al addition more sharply for the Sn–Al system than for the Ge–Al alloys. This is in qualitative agreement with the higher thermodynamic activity of the components of the Sn–Al alloys. Sn decreases Al surface tension more than Ge. The reason for this is not only lower surface tension of Sn as compared to Ge, but also the higher thermodynamic activity of Sn in the Al melt.     

Sb对锌液与X80钢表面润湿性影响的研究

目的通过添加不同量的Sb元素降低锌液表面张力,提升X80管线钢热浸镀锌可镀性及镀层质量。方法采用改良座滴法在450℃下进行润湿实验,利用轴对称液滴分析软件(ADSA),计算不同Zn-Sb合金熔体在X80钢基板上的接触角,得到450℃时Zn-Sb合金熔体表面张力。通过能谱仪和扫描电子显微镜对镀层表面及截面的微观形貌和组织结构进行分析。结果当Sb添加量为1.0%时,450℃下Zn-Sb合金表面张力约为0.63 N/m,随Sb含量的增加,表面张力逐渐减小,当Sb含量增加到4.0%时,表面张力达到0.46 N/m,远低于纯锌液的0.79N/m。同时,Zn-Sb合金熔体与X80钢的接触角也从最初的57°逐渐减小到43°。锌合金熔体与X80钢界面处形成铁锌化合物组成的连续反应层,且在反应三相线外存在前驱膜,前驱膜的形成使随后的合金液在其上铺展,促进了润湿。结论Sb的添加能有效降低锌液表面张力,减小Zn-Sb合金熔体与X80钢间的接触角。Sb的表面张力较小,倾向于在锌合金表面富集,其作为表面活性元素降低锌液表面张力,从而提高润湿性。     

Wettability and reactivity in diamond–borosilicate glass system

The wettability and interfacial reactivity between diamond and matrix are of great importance to their bonding strength and the applications, but the relating investigations are scarce. In this paper the wettability and interfacial reactivity in diamond–borosilicate glass system were studied by wettability measurements, thermogravimetry, scanning electron microscope, X-ray diffraction and Raman spectra. Results show an excellent wettability of the diamond by the borosilicate glass melt at temperatures above 700 °C. A distinct expansion with many irregular pores can be found in the diamond–borosilicate glass composites sintered above 800 °C, which caused by the oxidation of the diamonds. The start oxidation temperature of the diamond in the composites is 817.7 °C. So the quite compact bulk composites can be obtained below this temperature.     

Bi对锌液与X80钢表面润湿性的影响

通过改良静滴法研究Zn-xBi(x=0.5,1.0,1.5,2.0)合金熔体在450℃下与不同基板的润湿行为,对润湿反应之后的表面张力进行计算,并使用扫描电镜能谱仪(SEM-EDS)分析润湿试验后的试样表面及截面的微观形貌和组织结构。结果表明,在450℃下,Zn-Bi合金表面张力随Bi含量增加呈现先减小再增大的规律。Zn-1.0Bi合金熔体与X80钢的接触角最小,表明添加1.0%Bi(质量分数)后的锌液润湿性最好。Zn-Bi合金熔体中Bi的含量对界面反应强度和界面结构产生影响,进而减小表面张力和接触角。润湿初期Bi元素的快速吸附降低锌液表面张力,使接触角减小。中期由界面反应强度控制,此时形成前驱膜且其促进锌合金熔体在钢基板的流动,从而改善润湿性。     

TEMPERATURE DEPENDENCE OF VISCOSITY OF Al-Si ALLOY MELTS

1. IntroductionLiquid m etalsare in com m on use in m odern industry/area such ascasting, m etallurgy, w elding,glassform ing,the nuclearindustry and crystalgrow th.In addition,the relation ofthe physicalpropertyand structure change w ith tem perature, concentration and pressure isofgreatinterestto researchersinphysics and m aterials. V iscosity is a basic param eterin discussing the nature and behaviourofm etalm elts,and isone ofbasic propertiessensitive to the m eltstructure. V iscosity m ea…     

Effect of Nd and La on surface tension and wettability of Sn-8Zn-3Bi solders

Maximum bubble pressure measurement was employed to evaluate surface tension of Sn-8Zn-3Bi- （0-0.15）Nd and Sn-8Zn-3Bi-（0 -0. 15）La solder melts. Wetting balance method was used to measure wetting force and wetting time on Cu substrate of the two group solders. The experimental results show that minute amount of Nd or La addition to Sn-8Zn-3Bi solder causes significant decrease of the surface tension of the solder melts at 200 - 240 ℃ and Nd addition is more effective on reduction of surface tension than that of La. Nd or La addition has the effect on enhancing the wetting force of the solder melts on Cu substrate, which results from the de- crease of interracial tension between the solder melt and Cu substrate. The wetting force reaches the maximum when 0.1% Nd is added to the base alloy. The contact angle between Sn-8Zn-3Bi base solders and Cu substrate decreases with the addition of Nd or La and the minimum of the contact angle is obtained from the solder with 0.1% Nd addition.     

Tailoring surface quality through mass and momentum transfer modeling using a volume of fluid method in selective laser melting of TiC/AlSi10Mg powder

A selective laser melting (SLM) physical model of coupled radiation transfer and thermal diffusion is proposed, which provides a local temperature field. A strong difference in thermal conductivity between the powder bed and dense material is taken into account. Both thermo-capillary force and recoil pressure induced by the material evaporation, which are the major driving forces for the melt flow, are incorporated in the formulation. The effect of the laser energy input per unit length (LEPUL) on the temperature distribution, melt pool dynamics, surface tension and resultant surface morphology has been investigated. It shows that the surface tension plays a crucial role in the formation of the terminally solidified surface morphology of the SLM-processed part. The higher surface tension of the lower temperature metal near the edge of the melt pool and the thermal-capillary force induced by the surface temperature gradient tend to pull the molten metal away from the center of the melt pool. For a relatively high LEPUL of 750 J/m, the molten material in the center of the melt pool has a tendency to flow towards the rear part, resulting in the stack of molten material and the attendant formation of a poor surface quality. For an optimized processing condition, LEPUL=500 J/m, a complete spreading of the molten material driven by the surface tension is obtained, leading to the formation of a fine and flat melt pool surface. The surface quality and morphology are experimentally acquired, which are in a good agreement with the results predicted by simulation.