上盖冲压工艺与模具设计

根据某上盖零件的结构特点及技术要求,通过对各工艺方案进行分析比较,设计了落料-拉深-冲孔-翻边复合模,即在一个工位同时完成落料、拉深、冲孔和翻边4个不同工序的复合模结构.详细介绍了模具的工作过程及设计要点,解决了条料的定位、导向、卸料、出件、优化模具结构等技术问题.经实际生产验证,此套模具大大提高了生产效率,其合理的模具结构保证了上盖的形状及尺寸精度,提高了企业的经济效益.     

压簧簧片工艺分析与级进模设计

分析了压簧簧片的成形工艺,确定了冲压工艺方案,设计了7个工位的级进模,采用弹压卸料板及压杆将条料稳定在各工位上,保证条料在各工位间传递的平稳性和可靠性,模具制造成本低,能满足稳定、高效生产的要求。     

充电器接线负极片冲压工艺与模具设计

介绍了充电器接线负极片冲压工艺与模具设计,阐述了工位设计、排样图设计、模具结构及主要零件设计。生产实践证明,模具结构可靠,达到了技术要求和产量要求。     

锁片件多工位级进模设计

根据锁片零件的尺寸、结构和生产批量要求,进行了多工位级进模冲压工艺分析。为保证冲制过程中成形工位带料平整和良好流动,设计了3道工位完成工艺切口,确定了以冲孔、冲切、成形和整形为主的排样方案。对模具和主要零部件进行了结构设计,采用导料板配合导正钉定位,设计了内外导向机构和弹性卸料装置进行压料和卸料,保证了产品精度。加工模具后进行了试冲,结果表明,设计的排样方案和模具结构是合理的,得到的制件符合尺寸和精度要求。     

支架冲压工艺与模具设计

根据支架结构特点及技术要求,围绕如何提高生产效率、降低制造成本、简化模具结构,制订了复合模冲压成形的工艺方案.在冲裁复合模设计方面,解决了条料的定位、导向、卸料、出件、优化模具结构等技术问题.在弯曲、翻边、胀形复合模设计方面,借助"一面两孔"定位,解决了支架在成形过程中的偏移问题;通过控制成形模具的间隙,控制了弯曲回弹.实践证明,上述冲压工艺及模具设计生产效率高,模具结构合理,能保证支架的形状及尺寸精度.     

冰箱上、下梁冲压工艺改进及多工位传递模设计

分析了冰箱上、下梁现有冲压工艺,比较了3种工艺改进方案,提出采用多工位传递模代替单工序模冲压,设计了多工位传递模冲压排样图.为解决模具能在水平方向完成管夹槽的成形,而步进时又能够顺利脱离模具准确传递的问题,模具结构设计中采用了4种滑块结构.该模具已投入生产使用,工作稳定,制件质量符合要求.     

导纱针冲压工艺及模具结构设计

针对导纱针针坯的成形难点和技术要求进行了冲压工艺设计和多工位级进模具结构设计,详述了导纱针结构特点、 冲压工艺、 模具结构设计和工作零件的结构设计.为了防止条料塑性变形引起关键尺寸误差,模具对塑性变形区域一次成形;为保证针孔与外圆弧的同心度和送料精度,模具采用了导正块、 导料销和导正销进行精确定位;为保证冲孔凸模强度和刚度要求,模具采用保护套结构;为增加冲裁截面的光亮带,采用了两次整修工艺;为简化模具结构、 便于修模,采用了嵌块式凹模.生产实践证明,冲压工艺合理,模具结构安全可靠,产量质量稳定.     

计算机防护盖冲压工艺与级进模设计

分析了计算机防护盖冲压工艺,设计了相应级进模排样方案和模具结构,阐述了模具结构特点及主要零件和关键工位设计应注意的问题,并给出了解决措施。     

窗帘支架弹片多工位级进模设计

介绍了窗帘支架弹片多工位级进模的冲压工艺,设计了排样图及模具结构。说明了模具结构的特点,该模具的上、下模板具有高精度和长寿命,可快速更换凸模和凹模镶块,重复装配精度高。实践证明:模具结构可靠,加工质量合格,生产效率高,对此类零件的多工位级进模设计有参考价值。     

支撑架多工位级进模的设计

根据支撑架产品结构的工艺分析,研究了多工位级进模的工件排样,比较了不同的排样方案和载体形式.在不增加模具复杂程度和模具加工难度的前提下,采用工件斜排方式和条料两边不等宽双侧载体形式,设计了一套多工位级进冲裁弯曲模,与通常使用的工件横排方式相比,能够提高材料利用率3％.该套模具投入生产后,运行良好,生产的制件完全满足客户要求,为企业降低了生产成本.     

胫骨生物陶瓷复合材料的微结构增韧机理

扫描电镜观察显示胫骨是一种由羟基磷灰石和胶原蛋白组成的自然生物陶瓷复合材料.羟基磷灰石具有层状的微结构并且平行于骨的表面排列.观察也显示这些羟基磷灰石层又是由许多羟基磷灰石片所组成,这些羟基磷灰石片具有长而薄的形状,也以平行的方式整齐排列.基于在胫骨中观察到的羟基磷灰石片的微结构特征,通过微结构模型分析及实验,研究了羟基磷灰石片平行排列微结构的最大拔出能.结果表明,羟基磷灰石片长而薄的形状以及平行排列方式增加了其最大拔出能,进而提高了骨的断裂韧性.     

Features of formation of the structure in production of blanks of disks of heat-resistant nickel alloys

Conclusions To provide a high level of mechanical properties in wrought blanks of cast ÉP741NP and ÉP962 alloys it is necessary to form controlled structures. A necklace-type structure formed in homogenizing isostatic treatment, subsequent thermomechanical working including alternation of the operations of deformation in the (+)-area and recrystallization anneals, and final heat treatment is preferable. The temperature conditions of all stages of thermomechanical working are strictly controlled, especially the final operation of deformation and heating for hardening. To eliminate hardening cracks and distortions it is necessary to use molten salts at t=600°C as quenchants. The use of multiple production operations makes it possible to significantly reduce the structural inhomogeneity related to inhertance of the original dendritic structure. However, the structure of the final semifinished product is nevertheless characterized by a difference in occurrence of the processes of polygonization and recrystallization between the former dendritic cells and the interdendritic spaces in deformation and heat treatment.To obtain structurally homogeneous blanks for gas turbine engine parts it is necessary to use basically new methods of remelting such as vacuum double electrode remelting and electron beam remelting with an intermediate vessel.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 12, pp. 25–29, December, 1991.     

Ab-initio calculation of enthalpies of formation of intermetallic compounds and enthalpies of mixing of solid solutions

A large number of ab-initio calculations of energies of formation of intermetallic compounds have been performed in the last 15 years. The currently used methods are listed. The paper presents a review of the aluminium based compounds which have been studied. Comparisons of calculated and experimental enthalpies of formation are provided for aluminim-3d and-4d transition metal alloys at equiatomic composition. The modelling of the enthalpies of mixing of solid solutions based on a given lattice is described.     

试论洋务派教师聘任的思想

洋务派在洋务学堂的办学活动中,为了解决西学专业学科的教学困难,采用了聘请外籍教师的应急措施.他们以真才实学,合同制管理作为主导思想,并认为这种解决师资的途径只是权宜之计,并非久远.从客观上看,洋务派的教师聘任思想有深刻的历史影响.     

Prospects of the Use of Synergetic Approach to Solution of Problems of the Science of Nanomaterials

A synergetic approach to solution of problems of self-controlled synthesis of nanostructures and creation of self-organizing nanotechnologies is considered in connection with the superproblem of creation of materials with functional properties resembling those of biosystems. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 55 – 61, July, 2005.     

Kinetics of the oxidation of metals — Influence of self-diffusion of metal

The importance of the self-diffusion of a metal during its oxidation by a gas is treated for the cases of nonstoichiometric oxides having either interstitial cation or cation vacancies. We have established a general relationship for the reaction rate when a mixed diffusion process occurs. From this relationship, we have shown that the pressure dependence can be different, according to whether the rate-determining process is the self-diffusion through the metal or through the product.     

FeCrAIW电弧喷涂层组织的致密化研究

采用激光辐照对FeCrAlW电弧喷涂层的组织进行致密化处理,借助扫描电镜和X衍射对涂层的组织进行了分析.测试了涂层的显微硬度.结果表明:涂层组织致密度提高,孔隙率明显降低.随着激光扫描速度的增加,涂层的显微硬度降低.在较低的扫描速度下,涂层与基体之间形成互熔区,涂层与基体之间产生良好的冶金结合.