铸件缺陷修补方法

简述了铸件缺陷的谷种修补方法及工艺，指出液膜溶解扩散焊是一种比较先进的焊补方法。     

冷轧带钢板形缺陷表达式回归及数学模型

介绍了武钢冷轧厂１２５０ｍｍＨＣ轧机板形控制基本原理及冷轧带钢板形缺陷的板形分量表达式的回归处理和数学模型     

铜合金挤压材缩尾缺陷的控制办法

分析了铜合金制品缩尾缺陷的产生原因,并提出了相应的预防措施.有效减少缩尾缺陷,提高产品质量和经济效益.     

石墨的球状生长--球墨铸铁基础理论的最新发展(二)

球形晶体的结晶学条件要求雏晶必须有大量辐射对称的小角分枝;此外,这些小角度分枝应具备“规则分枝”特征（即相同的生长习性与生长速度）。在众多球化理论中,缺陷生长理论较符合球形晶结晶学原理,而石墨的缺陷生长与溶液结晶时的过冷有密切关系,化学成分、冷却速度等工艺因素都通过动力过冷、成分过冷、热学过冷影响石墨螺型缺陷决定最终生长成的石墨形状。对石墨球在奥氏体晕圈（壳）包围下生长过程进行了研究。用彩色金相方法揭示出奥氏体壳的形成过程并将奥氏体壳分为快封闭、慢封闭、不封闭三种类型,讨论了它们与石墨畸变的关系。快封闭的奥氏体壳保证得到圆整的石墨球,慢封闭与不封闭都使石墨形成畸形。     

304不锈钢精铸件点缺陷的形成与控制

针对典型304不锈钢精密铸件内出现的黑色点缺陷,对其表面形貌、成分进行了分析,并在此基础上总结了缺陷的形成机制,确定了相应的防止措施。研究结果表明,铸件内的点缺陷可以划分为两类:一类具有不规则截面,为脱蜡过程中剩余腊料的燃烧残留物;另一类为熔炼过程中,由于脱氧剂和除渣剂的去除不彻底而引入的夹杂。通过优化脱蜡和熔炼工艺,使得铸件内的点缺陷得到了很好的控制。     

数控小孔冲床网眼平板加工中的波浪纹缺陷成因分析及排除

文章就数控小孔冲床加工纺织烘干设备中帘子网眼平板产生波浪纹缺陷的原因,进行了全面、详细的理论分析.在排除机床、模具精度影响的基础上,针对压料机构运动误差产生的机理和不利影响,详细分析了网眼冲孔加工产生波浪纹缺陷的根本原因,提出了相应的改进措施,在实践中具有良好的实用效果.     

A modified embedded-atom method interatomic potential for the Fe–H system

A modified embedded-atom method (MEAM) interatomic potential for the Fe–H binary system has been developed using previously developed MEAM potentials of Fe and H. The potential parameters were determined by fitting to experimental data on the dilute heat of solution of hydrogen in body-centered cubic (bcc) and face-centered cubic (fcc) Fe, the vacancy–hydrogen binding energy in bcc Fe, and to a first-principles calculation for the lattice parameter and bulk modulus of a hypothetical NaCl-type FeH. The potential accurately reproduces the known physical properties of hydrogen as an interstitial solute element in bcc and fcc Fe. The applicability of the potential to atomistic approaches for investigating interactions between hydrogen atoms and other defects such as vacancies, dislocations and grain boundaries, and also for investigating the effects of hydrogen on various deformation and mechanical behaviors of iron is demonstrated.     

ZnO压敏陶瓷的非线性功能添加剂

本文采用单元掺杂与多元掺杂的方法，系统研究了几种过渡金属氧化物添加剂在控制ＺｎＯ压敏陶瓷非线性方面的作用，并根据金属阳离子外壳层电子结构稳定性和缺陷化学反应进行了分析，认为阳离子具有不饱和外层电子结构且半径与Ｚｎ＾２＋离子相近的过渡金属氧化物能改善ＺｎＯ压敏陶瓷非线性。     

5000m3液氨球罐缺陷分析

介绍建峰化工总厂化肥厂液氨球罐在进行周检时发现的缺陷及状况。针对不同类型缺陷 ,对其出处、成因按相关标准理论进行详细分析 ,运用规程进行强度校核、评定 ,得出球罐在下一检验周期前仍然安全可靠 ,提出了预防措施和建议     

Stochastic defect diffusion model for relaxation effects in crystalline polyethylene

It is suggested that some relaxation processes observed in crystalline polyethylene are consequences of the diffusive motion of a particular defect called a point dislocation or twist dispiration loop along the polyethylene stems in lamellar crystals. The motion of the defect, characterized by a diffusion coefficient and a mobility, is described by solutions of the Smoluchowski diffusion equation with boundary conditions that constrain the defect to move along routes that produce experimentally observable results. The fact that passage of the defect causes both a 180° rotation of the chain and moves an extra CH₂ group in the direction of the chain axis is important to the interpretation of the data according to this model. The diffusion coefficient for a defect is estimated to be around 2 × 10^?9 cm² s^?1 at 70°C. This value is shown to be reasonable both from the viewpoint of detailed computer modelling of defect motion and contemporary ideas about scaling.