双零铝箔铸轧工艺对其坯料质量影响的简述

简述了国内双零铝箔的质量状况及存在的问题,针对国产的大部分铸轧坯料由于内部组织结构等原因造成的铝箔在后续生产加工过程中断带频繁、针孔多、成品率低的问题,从合金成分、晶粒细化、熔炼温度及铸轧工艺参数方面对铸轧坯料质量的影响情况进行了分析,探讨了提高双零铝箔铸轧坯料质量的措施。     

电解铝液直接生产超薄箔坯料的熔体质量控制

针对电解铝液直接铸轧坯生产超薄铝箔坯料过程中所存在的质量缺陷,结合铸轧法生产铝箔坯料所采用电解铝液的特点,全面分析了生产过程中铝合金熔体处理工艺对熔体质量的影响因素,并研究制定了相应的铝熔体处理措施。有效改善了熔体质量,消除/减少了电解铝液生产超薄铝箔坯料的质量问题,实现了低成本、高效率、高品质、稳定生产超薄箔坯料的目标。     

电解铝液铸轧生产3003阴极铝箔坯料质量控制

分析了用电解铝液直接生产3003阴极铝箔坯料的质量问题以及铸轧板质量缺陷的影响因素,阐述了生产铸轧坯料的原辅材料、熔体处理、晶粒细化、板形控制、铸轧辊表面质量的控制措施,提高了铸轧坯料的质量,有效地控制了阴极铝箔的针孔数量和偏析.     

铝液过滤工艺对超薄双零铝箔质量的影响

超薄双零铝箔由于附加值高、经济效益突出而受到现代铝箔加工企业的重点关注,但铸轧坯料质量的稳定性直接影响成品超薄铝箔质量.本试验通过研究铝液的过滤工艺对铸轧坯料质量的影响,进而导致超薄双零铝箔针孔数和成品率的变化,探索陶瓷过滤板对铝液过滤的最佳净化时段,确定合理的过滤工艺.     

简析铸轧双零箔坯料生产时电解铝液的应用

简述了双零箔的质量要求、电解铝液的特点,以及使用电解液产生的缺陷对铝箔的影响;研究了铸轧使用部分电解铝液生产铸轧双零箔坯料的工艺方法。     

1235铝合金双零箔用铸轧坯料的生产工艺

铸轧坯料的质量是生产出合格0.0060 mm双零铝箔的关键因素。通过从炉内、在线对铝熔体的净化处理,精确控制合金成分,采用高效的除钠工艺,用倾斜式铸轧机,合理设计铸轧工艺等系列措施,生产出满足双零烟箔用的1235合金铸轧坯料。     

电解铝液直接生产1235合金双零箔铸轧坯料的工艺研究与实践

铸轧坯料的质量是生产合格0.0065mm双零铝箔的关键因素。通过从炉内、在线对铝熔体的净化处理,精确控制合金成分,采用高效的除钠工艺,用立式铸轧机,合理设计铸轧工艺,不断优化工艺参数,生产出满足双零烟箔用的1235合金铸轧坯料。     

铸轧坯料轧制幅宽≥1300mm的双零箔生产工艺研究

随着铝箔应用领域及需求量不断增加,国内铝箔工业不断发展,尤其是软包装用铝箔产业发展迅速。除了电解电容器中使用高质量的双零铝箔外,在包装用铝箔中,90%以上为双零铝箔。结合我厂目前箔材生产实际,通过对铸轧坯料轧制幅宽≥1 300 mm的双零箔工艺研究,确定了采用高硅1145铝合金铸轧坯料生产优质宽幅双零箔的生产工艺,使幅宽≥1 300 mm的双零铝箔实现了批量化生产,并且表面质量在同行业中处于优等品层级。     

0.009～0.01mm高档啤酒标用合金箔工艺研究

研究用8011合金铸轧坯料生产啤酒标用铝箔的生产工艺。探讨生产工艺、中间退火和成品退火制度对铝箔力学性能的影响     

双零六铝箔坯料已进入批量生产

经过艰苦努力,中铝公司瑞闽铝板带有限公司与青海分公司合作的电解铝生产双零六铝箔坯料项目已经入批量生产,该项目的成功开发,减少了能耗和烧损,每年在节能减排上创效1120万元。随着电解铝水熔体质量控制、电解铝水铸轧生产晶粒细化等关键技术的突破,所有铸轧产品,包括高档的铝箔坯料、PS版基等均能通过此项技术,并直接使用铝水生产,可以产生巨大的社会效益和经济效益。     

Behaviorally measured refractory periods are lengthened by reducing electrode tip exposure or raising current.

Measured the effects of current and tip surface area on stimulation parameters required to produce a constant rate of self-stimulation of lateral hypothalamic sites or of circling when stimulating medial brain stem sites. Data from 20 male Wistar rats show that thresholds for circling decreased when tip surface area was decreased to 0.01 mm–2. Refractory period curves for both circling and self-stimulation were shifted to slightly longer intrapair intervals when tip surface area was decreased or current was increased. This suggests that long refractory period axons make larger contributions when current density is increased. Chronaxies were not lengthened by small tip exposures but were reduced when electrodes were placed far lateral to the circling substrate. Threshold differences between axons stimulated by different tip exposures and currents are discussed. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

30MnSi管桩钢筋镦头开裂原因浅析

从盘条和管桩生产工艺等方面，分析30MnSi管桩钢筋镦头开裂的原因，认为除传统上的钢筋热处理和盘条钢质两类影响因素外，表面划伤和折叠等线状缺陷也会造成镦头开裂，对比作重点分析。     

粗轧过程轧件表面裂纹演变行为热力耦合有限元分析

 连铸坯可能出现表面裂纹,其在轧制过程中的演变行为严重影响着轧制产品的质量。本文采用热力耦合有限元方法对轧制过程轧件表面裂纹演变行为进行了分析。获取了轧制过程中轧制变形区内轧件表面裂纹形状变化规律、裂纹附近区域应力场和温度场分布场分布情况。计算结果表明在轧制入口区域,裂纹逐渐闭合,然而,在轧制出口区域,裂纹又重新扩展开,裂纹尖端处呈现拉应力状态。同时,发现变形区内裂纹尖端发生温度成双峰变化规律。     

A physical approach to reduce nonspecific adhesion in molecular recognition atomic force microscopy

Atomic force microscopy is one of the few techniques that allow analysis of biological recognition processes at the single-molecule level. A major limitation of this approach is the nonspecific interaction between the force sensor and substrate. We have modeled the nonspecific interaction by looking at the interaction potential between a conical Si3N4 tip with a spherical end face and a mica surface in solution, using DLVO (Derjaguin, Landau, Verwey, Overbeek) theory and numerical calculations. Insertion of the tip-sample potential in a simulation of an approach-retract cycle of the cantilever gives the well-known force-distance curve. Simulating a force-distance curve at low salt concentration predicts a discrete hopping of the tip, caused by thermal fluctuations. This hopping behavior was observed experimentally and gave rise to a novel approach to making measurements in adhesion mode that essentially works in the repulsive regime. The distance between tip and sample will still be small enough to allow spacer-involved specific interactions, and the percentage of nonspecific interactions of the bare tip with the mica is minimized. We have validated this physical model by imaging intercellular adhesion molecule 1 (ICAM-1) antigen with a tip functionalized with anti-ICAM-1 antibody. The measurement demonstrated that a significant decrease in the number of nonspecific interactions was realized, and the topographical image quality and the specific bonding capability of the tip were not affected.     

保护渣对连铸异型坯表面质量的影响

文中分析了结晶器保护渣对连铸异型坯质量的影响，主要讨论了异型坯腹板纵裂纹、表面针孔及翼缘端部凹陷等铸坯质量缺陷，特别是对表面针孔缺陷做了热力学计算，从理论上分析了异型坯产生缺陷的原因，提出了适合马钢异型坯连铸结晶器保护渣的主要指标和性能。     

楔横轧小断面收缩率轧件螺旋组织缺陷研究

轧件发生局部变形是楔横轧的主要工艺特征,尤其小断面收缩率轧件轴向流动能力弱,内外变形差异显著导致楔横轧成形困难.除了容易产生心部破坏缺陷,在轧件表层一定范围内出现的螺旋组织缺陷,也会降低产品的机械性能.本文通过轧制实验,展示出轧件螺旋组织缺陷宏观上呈现为车削后在表层一定深度范围内沿展宽螺旋线分布的亮带,微观上由轧件表面折叠向内部延伸呈带状分布的组织形态.结合有限元数值模拟方法研究了缺陷产生的主要原因,发现由于成形区的金属发生沿展宽负向的金属流动,导致轧件形成沿展宽螺旋线分布的表面折叠和小轴向应变带.同时,螺旋带附近较大的径向压缩使轧件由表面向内部沿折叠裂纹方向组织具有方向性.采用对模具楔尖倒圆角局部改善金属沿负展宽方向的轴向流动,可以既消除表层螺旋组织缺陷,又避免轧件心部损伤风险,使成形质量满足使用要求.经实验验证,确定了模具楔尖圆角的最优取值.      

Analysis of Crack Tip Stress of Transversal Crack on Slab Corner During Vertical-Horizontal Rolling Process by FEM

Behavior of transversal crack notched on slab corner during vertical-horizontal rolling process was simulated by FEM. The crack tip stress in the whole rolling process was obtained. Influences of the friction coefficient, the initial crack size, the edger roll profile, and the groove fillet radii of grooved edger roll on crack tip stress were analyzed. For vertical rolling, the tension stress appears at crack tip near the slab top surface and the compression stress appears at crack tip near the slab side surface for the flat edger roll; however, the compression stress appears at crack tip near the slab top surface and the tension stress appears at crack tip near the slab side surface in the exit stage for the grooved edger roll. For horizontal rolling, the tension stress appears at crack tip just at the exit stage for the flat edger roll, and the tension stress appears in whole rolling stage; the tension stress value near the slab side surface is much larger than that near the slab top surface for the grooved edger roll.     

Monopolar needle electrode spatial recording characteristics

The recording characteristics of the monopolar needle in three dimensions have not been well established. A simple spherical recording territory is commonly assumed with the very tip proposed to have a greater spatial recording sensitivity by some authors. We demonstrate by enlarged physical modeling in a homogeneous volume conductor that the recorded amplitude diminishes more gradually radially away from the conical surface than distally past the tip or proximal to the insulation edge. The sensitivity over the exposed metallic surface is found to be uniformly proportional to the area, which results in relatively less sensitivity at the tip than the middle and proximal portions of the conical recording surface. The overall spatial amplitude recording characteristics can be better described by an apple shape than a sphere, centered at the midportion of the exposed conical surface. A better appreciation of the actual spatial recording characteristics of the monopolar needle electrode can result in more accurate physiologic interpretations of quantitative motor unit analysis.     

Mode I stress intensity factors induced by fracture surface roughness under pure mode III loading: Application to the effect of loading modes on stress corrosion crack growth

A model to estimate the reduction of effective crack tip Mode III stress intensity factors by frictional and asperity interaction of an idealized fracture surface is described. An extension of the model is used to calculate the Mode I stress intensity factors due to the crack tip opening displacement induced by the mismatch of the fracture surface asperities. The results of calculations based on a “reasonable” fracture surface profile are used to analyze experimental studies designed to determine the relative significance of hydrogen embrittlement and crack tip dissolution in stress corrosion crack growth in Al alloys by comparison of Mode I and Mode III stress corrosion cracking (SCC) resistance. It is concluded that a pure Mode III stress state is not possible for cracks with microscopically rough surfaces and that the magnitude of the induced Mode I stress intensity factor is sufficient to cause stress corrosion crack growth.     

The height of biomolecules measured with the atomic force microscope depends on electrostatic interactions

In biological applications of atomic force microscopy, the different surface properties of the biological sample and its support become apparent. Observed height differences between the biomolecule and its supporting surface are thus not only of structural origin, but also depend on the different sample-tip and support-tip interactions. This can result in negative or positive contributions to the measured height, effects that are described by the DLVO (Derjaguin, Landau, Verwey, Overbeek) theory. Experimental verification shows that the electrostatic interactions between tip and sample can strongly influence the result obtained. To overcome this problem, pH and electrolyte concentration of the buffer solution have to be adjusted to screen out electrostatic forces. Under these conditions, the tip comes into direct contact with the surface of support and biological system, even when low forces required to prevent sample deformation are applied. In this case, the measured height can be related to the thickness of the native biological structure. The observed height dependence of the macromolecules on electrolyte concentration makes it possible to estimate surface charge densities.