摆辗机新型椭圆运动轨迹的研究

具有双偏心套的摆辗机摆头运动轨迹较为复杂,本文针对直线运动轨迹中的摆头在交变成形力的作用下会导致摆头轴断裂问题,根据摆头运动原理,建立摆头运动方程,提出并分析了摆头新型椭圆运动轨迹,改善了摆头受力状况;并总结椭圆运动轨迹变化规律,为改进摆头结构、设计新型摆辗机、拓展摆辗成形工艺提供理论指导。     

摆辗机螺旋线和多叶玫瑰线的三维成形轨迹仿真

具有双偏心套结构的摆辗机摆头可以实现多种运动轨迹,螺旋线和多叶玫瑰线运动轨迹形状较为复杂,为了直观显示及分析摆头螺旋线和多叶玫瑰线运动轨迹的摆辗成形过程,根据摆头运动原理,建立摆头运动方程;应用MATLAB软件,针对摆头螺旋线和多叶玫瑰线运动轨迹进行仿真模拟,分析摆头三维运动轨迹的形成及规律。研究结果可直观显示摆头螺旋线和多叶玫瑰线运动轨迹成形过程,对于运动轨迹成形过程中摆角大小、摆头受力、摆辗机运动轨迹参数的选用和成形工艺制定均具有现实指导意义。     

摆动辗压成形件高度尺寸精度分析

扼要介绍了摆动辗压成形过程的工作原理及摆头运动轨迹；详细分析了摆头运动倾有（即摆角）的大小与摆头锥角不匹配和摆辗中心的偏移对摆动辗压成形件高度尺寸精度的影响，探讨了国内个摆辗机的合理应用范围，指出只有摆角较小的摆辗机才宜于净形与近似净形加工摆动辗压成形件。     

摆辗机新型螺旋线运动轨迹研究

针对双偏心套摆辗机摆头的螺旋线运动轨迹,根据摆头运动原理,建立摆头运动方程,提出并分析摆头新型螺旋线运动轨迹的形成,总结该运动轨迹变化规律,为改进摆头结构、设计新型摆辗机、拓展摆辗成形工艺提供理论指导。     

摆辗机新型多叶玫瑰线的运动轨迹

摆动辗压是一种局部成形的加工方法,特别适用于盘类及薄扁状零件的成形。摆动辗压机的摆头运动轨迹较为复杂,该文针对多叶玫瑰线运动轨迹中的摆头在交变成形力的作用下会导致摆头轴断裂,较深入的分析和研究双偏心套摆辗机摆头的多叶玫瑰线运动轨迹特点,根据摆头运动原理,建立摆头运动方程,提出并分析摆头新型多叶玫瑰线运动轨迹的形成与规律,改善摆头受力状况。研究工作不仅可以解决通常一些设计中摆头在交变成形力的作用下导致的摆头轴断裂,而且对于改进传统的摆头结构、设计新型摆辗机和拓展摆辗成形工艺提供了理论指导。     

PXW型摆辗机摆头运动学分析及摆头运动轨迹研究

基于PXW型摆辗机摆头运动特点及结构特征,借助双偏心套机构运动模型,通过运动学分析建立摆头矢量运动方程,并研究摆头4种运动轨迹形成特点;利用Matlab软件对异速同向双偏心套的运动轨迹进行了模拟仿真,分析摆头螺旋线轨迹形成过程。     

不等偏心距对摆头运动影响的研究

在摆辗成形过程中,摆头除圆轨迹外的玫瑰线、螺旋线和直线轨迹,由于内外偏心套转速不相等,会形成较大的振荡离心力,从而使机身产生剧烈的晃动,极大降低设备使用寿命和零件加工精度。本文研究了四种轨迹摆辗成形中不等偏心距对摆头运动状态的影响规律,并推导出减小摆头振动的内外偏心套偏心距关系式,这对摆辗机的结构优化与应用推广有指导意义。     

摆辗机摆头运动学分析和运动轨迹的数值模拟

从摆动辗压机中摆头的结构出发,通过运动学分析给出摆头运动方程,采用数值方法对摆头运动轨迹进行数值模拟,为摆辗机结构设计和摆辗工艺的合理应用提供了科学依据。     

PXW型摆辗机摆动机构运动学问题初探

给出了ＰＸＷ型摆辗机摆头运动机构的机构运动简图,并据此认为具有多种摆头运动轨迹之摆辗机摆杆轴线上除顶点以外的各点只能是作球面运动,因而以往在摆头运动轨迹分析中其简化为平面杆系势必引入误差。     

摆辗运动轨迹及调整曲线的分析研究

推导了摆辗机摆头的运动轨迹方程，分析了内外偏心套转速比μ与四种轨迹的关系，并给出了摆辗机的两条调整曲线以及计算多叶玫瑰线轨迹叶数和螺旋线轨迹圈数的方法。     

摆动辗压成形工艺研究现状及发展

摆动辗压作为锻造成形技术之一,具有节能、高效、低噪音等优点。该技术在国内外已经成为成形加工研究的热点,并在企业逐渐得到推广和应用。本文介绍了摆动辗压成形的工作原理、工艺特征以及摆动辗压设备及摆动辗压技术在国内外研究进展和应用现状,并对摆动辗压技术的未来发展趋势和方向进行了分析。     

摆辗机摆头4种运动轨迹的模拟与分析

针对国外摆辗机摆头4种运动轨迹的运动原理,推导摆头运动方程,用UG NX三维设计软件建立驱动摆头运动的内、外偏心套结构模型,对摆头运动仿真模拟,理论分析摆头4种运动曲线,验证仿真模拟结果。     

类金刚石膜的性质和制备及应用

介绍了类金刚石膜的性能、制备方法以及应用.类金刚石膜(DLC)是由sp3键组态的碳和sp2键组态的碳混合组成的碳材料,由于具有与金刚石膜(DF)相似的性能--优异的光学特性、机械特性、电学特性和化学特性,同时现行制备方法(化学气相沉积,物理气相沉积等)相对容易实现,并且其产品已经应用到光学、医学、机械、电子等多个领域,因此引起人们极大兴趣.     

Using orbital welding in the manufacture and repair of thin wall pipelines

The possibilities and practical aspects of application of orbital welding for pipelines in aviation gas turbine engines are investigated.     

Influence of welding position and parameters in orbital tig welding applied to low-carbon steel pipes

The most notable characteristic of Orbital TIG welding is the constant geometric profile of the tubes. In the context of orbital TIG welding of tubes with a large diameter and thick walls, the relationship between the welding position, the use of constant or pulsed current and also the value of the average current on the geometric characteristics of the beads obtained was studied. We deposited welds on SAE 1020 carbon steel tubes, as well as taking macrographs of the cross-sections of the beads using optical microscopy. High-definition films were used to understand the behaviour of the weld pool in different welding positions. The geometric characteristics were quantified using macrographs and software, and the relationship between these characteristics and the above-mentioned variables were traced. In addition, an analysis of the microstructure of the samples was carried out, correlating with Vickers microhardness. It was concluded that the beads welded with pulsed current were more reinforced and wider, as well as being harder and having a finer microstructure. The vertical up position resulted in beads with a lower shape factor and more penetration, and the overhead position resulted in beads with a low shape factor.     

氧气在铀钼体系表面吸附和解离行为的第一性原理研究

基于第一性原理探究了氧气分子在铀钼表面的吸附解离行为。在五层γ-U(100)表面构型的基础上,用单个钼原子置换表层的1个高对称点的铀原子,并用4个钼原子置换表层铀原子后,分别建立了γ-U(100)/Mo和γ-U(100)/4Mo模型,计算得到了不同吸附构型下的结构参数、吸附能、Bader电荷、电子结构和表面功函数。结果表明,氧分子在γ-U(100)/Mo和γ-U(100)/4Mo表面为化学吸附,且最稳定的吸附位点为空位平行吸附,吸附能分别为-12.552和-8.661 eV。氧分子在铀钼表面的吸附分为解离吸附和未解离吸附,两者共同组成稳定的吸附行为,同时,解离吸附比未解离吸附更为稳定。Bader电荷结果表明,氧气在吸附过程中,主要与吸附表面最上两层的原子发生电荷转移。电子结构研究表明,O 2s和U 6p轨道发生轻微杂化,O 2p与U 6d、Mo 5s、Mo 4p、Mo 4d轨道发生较强的重叠杂化。本研究为氧分子在铀钼合金表面的吸附提供了机理阐述,并进一步为氧气在铀钼合金表面的腐蚀机理研究提供理论基础。     

电火花摇动加工微细阵列轴和孔的试验研究

针对微细阵列轴和孔的电火花加工,提出了利用数控电火花加工机床摇动功能的摇动加工微细阵列轴和孔的方法.此法是基于电火花反拷贝加工的原理,先用丝电极在薄平板(中间电极)上按要加工的阵列轴和孔间距或数倍间距加工阵列小孔(直径0.1 mm以上),然后用加工的薄平板(中间电极)作电极,电火花摇动加工微细阵列轴(电极),最后用此微细阵列电极加工阵列孔.进行了电火花摇动加工微细阵列电极试验,得到了单电极直径为50 μm、长径比为16的3×3阵列电极,并用此电极在70 μm厚的不锈钢板上加工出单孔直径为70 μm的3×3微细阵列孔.试验结果表明,电火花摇动加工方法可实现微细阵列轴和孔的加工.     

First-principles theory on electronic structure and floatability of spodumene

The band structure, density of states, Mulliken populations, and frontier orbital of spodumene crystal were calculated using the first-principles method based on the density functional theory(DFT) and further analyzed in detail. The calculation results reveal that the O in spodumene is the most active and easily links with H+in the water, but the active Li is very low, so it is better to add activator to increase the concentrate grade and recovery rate of spodumene in the flotation process. Si–O bonds in spodumene crystal are mainly covalent, since the covalency of Al–O bonds is stronger than that of Li–O bonds,and minerals dissociate along the weakest Li–O bonds. In addition, the study of the frontier orbital indicates that both O and Si atoms have large contribution to the frontier orbital in the spodumene crystal. Oleate and dodecylamine are used as the collectors of spodumene. The results contribute to the understanding of crystal structures of spodumene, and can be used in guiding related practical applications.     

摆动辗压在兵器行业的应用

根据摆动辗压的工作原理及其在中国的发展历程,介绍了国内摆动辗压的理论研究成果和工艺实践;重点叙述了摆动辗压在兵器零件生产中的应用,其中,轴向齿圈、自锻破片药形罩、药筒底板件的摆辗成形具有很高的实用价值及优势;最后讨论了摆动辗压更复杂零件、摆动辗压粉末冶金件以及提高摆动辗压件精度的发展方向。     

APPLICATION OF MOLECULAR ORBITAL THEORY TO ANALYSIS OF PHASE STABILITY FOR ALLOYS

The critical _d vahues ( _ ) of the γ/(γ+σ).γ/(γ+μ) and γ/(γ+γ') phase boundaries insome ternar alloy phase diagrams at various temperatures are calculated by averaging the _d values of sererai selected characteristic points at the phase boundaries.Approxmateequations for the temperature dependence of the critical _d of γ/(γ+σ).γ/(γ+μ) andγ/(γ+γ') phase boundaries are established.The accuracy of the analysis is discussed in detail.It is found for the first time that the average value of the bondorder _ at the phase boundaries ts also approximatelr a constant and therefore a criticalaverage bond order _ like - can be introduced for the analysts of phase stability