新型精密冷挤成形脱模装置设计与应用

分析了旋转顶出脱模方法的原理,并计算重要参数螺旋升角,设计出合理旋转顶出脱模装置,最后通过工艺试验证明旋转顶出脱模装置具有脱模阻力小,成形精度高等优点。     

Ab initio molecular dynamics simulation for structural transition of Zr during rapid quenching processes

We report the results of ab initio molecular dynamics simulation for the structural transition of Zr during two distinct quenching processes (Q1: 4.3 × 10¹³ K/s, Q2: 2.0 × 10¹⁴ K/s). In both the quenching processes, structural transition details have been analyzed by pair correlation functions g(r) and bond pair analysis technique. It is shown that the liquid Zr transforms to a metastable bcc phase (β-Zr) at the temperature about 1000 K as quenched at the rate of 4.3 × 10¹³ K/s. When quenched at 2.0 × 10¹⁴ K/s, however, the crystallization is suppressed and the liquid Zr is frozen into a glass state. The bond pair analysis reveals that the dominant bond pairs in the liquid and glass states are the 1551, 1541, 1431, 1661 and 1441, indicating that the short range order in both states mostly consists of icosahedral, tetrahedral and bcc clusters.     

轴角编码器在同步丝杆运动中的应用

介绍了增量式和绝对式编码器在同步丝杆控制中的应用和软件编制。     

φ3.6m×6.0m溢流型球磨机进料端与出料端的改进

针对 3.6m×6.0m球磨机设计存在的缺陷 ,分析了其进料端与出料端漏浆、出料口固定螺栓易被剪断的原因,提出了对其漏浆和固定螺栓被剪断进行改进的有效措施 ,取得了较好的效果     

Bonding wire characterization using automatic deformability measurement

A promising way to control underpad chip damage in IC packaging caused by wire bonding forces would be to use new wire chemistries that produce softer free-air balls (FABs). The number of new wire types that can be tested is limited by the available resources. The conventional FAB hardness characterization method is the microindentation test, a labour intensive and off-line task requiring cross-sectioning of a large number of samples. To accelerate FAB hardness characterization, an innovative on-line method is studied and presented here, enabling the fast comparison of different wire types. Collection of data from an instrumented wire bonder allows comparison of the deformability, i.e. the average amount of FAB deformation under a defined load. Increased deformability implies a softer FAB. The influences have been studied of changes in capillary, bonding substrate metallization and substrate temperature on the results obtained. It is found that these influences need to be held constant during a comparison study.     

储冰球相变传热数值计算及分析

对圆球形相变储冷器的相变传热问题进行了详细分析，采用焓法模型对常用相变介质水在球内的凝结过程进行了数值求解，得出了第一类边界条件下的相变界面位置变化与界面部移动速度变化以及相奕时间与球径和传热温差的关系等结果，可以为圆球形及其它形状的相变储的设计和分析计算提供理论依据与参考。     

氧化钇湿式球磨过程中的解聚机理研究

将氧化钇粉体在水性介质进行不同时间的球磨解聚 ,分别测定了粉体粒径、比表面积、ξ-电位以及体系p H值 ,得知球磨 6小时后可获得最佳的解聚效果 ,时间过长会导致二次团聚的发生。采用反聚集强度参数对这一过程进行了解释。     

国产1000m/min纸机基础板的安装

本文主要就造纸机的基础板安装方案、基础板安装规范和安装实施等过程作详细介绍.     

深沟球轴承振动的灰自助评估

利用乏信息理论中的灰自助融合与灰预测,建立深沟球轴承振动特征参数的动态灰自助频率函数,并对振动特征参数进行区间估计、动态不确定度分析及基于振动时间段的稳定性分析。结果表明:动态不确定度可以准确描述深沟球轴承基于振动时间点的数据波动状况;平均不确定度可以定量而准确地描述轴承基于振动时间段的数据波动及离散状况,且试验结果与计算结果非常接近,满足工程需要。