陶瓷内衬复合铜管的自蔓延高温合成

研究了离心自蔓延高温合成陶瓷内衬复合铜管工艺中离心力和添加剂对复合铜管性能的影响。结果表明：随着离心力增大，陶瓷层的孔隙度降低，压溃强度和压剪强度明显提高，离心力超过200G后，压剪强度反应降低。铝热剂中加入SiO2也可降低孔隙度，提高压剪强度。提高铝热剂预热温度，可加快铝热反应速度，改善复合铜管质量。     

近代离心雾化的概况

所谓离心雾化,就是采取某种形式的装置,利用离心力将熔融金属粉碎成粒状物。离心雾化通常包括有:旋转园盘法、旋转电极法和旋转坩埚法,如果说旋转国盘法是古老的话,那么旋转电极法与旋转坩埚法则是近代离心雾化了。旋转电极法的含意是:自耗转动电极与固定电极间产生电弧,将自耗电极熔化成液体,在离心力作用下,熔融金属被粉碎。常用氩气或氦气保护。而旋转坩埚法的含义是:用一根自耗电极与旋转的水冷坩埚建立起电弧,使自耗电极熔化流入旋转着的坩埚中,然后在离心力的作用下,熔液越过坩埚壁飞散成粉末,整个熔融雾化过程是在密闭容器中和控制气氛下完成的。     

陶瓷内衬复合铜管制造方法

本发明公开了一种用于管坯结晶器的铜管表面内衬陶瓷方法。在铜管内放入由CuO和Al配制而成的铝热荆，铝热荆中还含有2％-8％的SiO2、1％～5％的CrO3、2％-4％的Na2840—7和2％-8％的ZrO2，置于离心机上，启动离心机，而后点燃铝热剂，使其产生3CuO＋2Al→Al2O3＋3Cu＋1194．41d／mol铝热反应，铝热反应放出的热量，使生成物瞬间熔化。熔融态生成物在离心力作用下，根据其自身密度不同而分离，冷却之后形成了Al2O3陶瓷内衬复合铜管，Cu形成过渡层。本发明陶瓷内衬复合铜管的陶瓷层硬度高，耐磨性好，使用中不开裂、不剥落，陶瓷磨损均匀，复合铜管强度高、导热性好，使用中不变形，对冷却水没有特殊要求，复合铜管使用寿命达到普通铜管的25～3．0倍，比镀铬铜管寿命延长50％～80％。     

离心铸造铝铜合金缩孔缺陷研究

对离心铸造铝铜合金中缩孔缺陷的形态,以及旋转速度和旋转时间对缩孔缺陷体积的影响进行了深入研究.结果表明:离心力场下铝铜合金缩孔缺陷的方向都偏向于旋转中心,缩孔缺陷的最深处和缺陷位置都靠近横浇道垂直中心线;随着旋转速度的增加,铸件中缩孔缺陷体积先减小后增大,与离心力场旋转时间900 s时相比,旋转时间30 s时冒口以及铸件处的缩孔缺陷体积均减小,冒口对铸件处缩孔缺陷的补缩效果减弱.     

DMC复合材料自动切割机的研发

研发一台自动切割机,对DMC复合材料进行自动切割,用于制造窨井盖。要求切割机边输送复合材料边进行纵向和横向切割,且使得切口形状尽可能平齐。纵切机构是转轴带动圆盘切刀对复合材料进行纵向切割。横切机构是采用曲柄滑块机构驱使切刀对复合材料进行横向切断。运用MATLAB仿真,对横切机构切刀运动轨迹进行优化,得出物料切口最接近垂直的轨迹线。结果表明:当切刀口距离连杆与曲柄转心的距离为55 mm,曲柄角速度为26 r/min时,物料横向切口形状的左右最大偏差最小,最接近平齐标准,满足生产要求。     

砂质涂料离心喷涂的研究

离心喷涂砂质涂料是连续供给的砂质涂料在高速旋转的特制离心头中细分成微滴，并借助于离心力作用飞出，在已预热至220℃左右的金属铸型内壁上均匀堆积形成涂层。与喷枪喷涂相比，可以使涂料的含水比例降低，金属铸型的冷却速度减小，从而使金属铸型的预热温度降低；离心头和金属铸型的同轴反向双重旋转，使涂层更加均匀。离心喷涂方法可以用于大型轧辊离心铸造，以及大直径金属管件内壁防腐、耐热、耐磨涂层的生成。     

离心铸造污水管生产技术在设计中的应用

离心铸造污水管生产技术在设计中的应用马鞍山钢铁设计研究院章钢跃离心法生产铸铁管是把高温的铁水，浇入旋转的金属铸型，在离心力的作用下使铁水均匀分布在铸型的工作表面上，冷却凝固，获得壁厚均匀，组织致密的铸铁管子。采用离心法生产污水管，生产效率高，管子质量...     

专利

<正>专利名称:中频淬火感应器大直径矩形铜管的弯圆装置专利申请号:CN201220184281.7公开号:CN202610265U申请日:2012.04.27公开日:2012.12.19申请人:上海宝钢工业技术服务有限公司本实用新型公开了一种中频淬火感应器大直径矩形铜管的弯圆装置,即在工作台上通过定位销设置旋转靠模,旋转靠模一侧设置定位模,前后固定铁墩分别设于所述工作台两侧,铁棒穿入前固定铁墩通孔后固定连接固定铁板,螺栓穿入定型模后通过连接环后连接铁棒,C形夹具设于旋转靠模周边,定滑轮设于后固定铁墩上,铁链围绕旋转靠轮外圈并一端通过卸扣连接C形夹具、另一     

离心铸造铝铜合金显微组织梯度分布规律

研究了离心力场下,铝铜合金铸件在相同离心半径不同位置处宏观组织以及相和元素含量的梯度分布规律。结果．表明：铝铜合金铸件两侧的晶粒尺寸以及Al2Cu相和Cu元素含量均低于中心处。随着旋转速度的增加,铝铜合金铸件的宏观组织以及相和元素含量的梯度分布趋势增大。此外,铸件中心线两侧的宏观组织以及相和元素含量具有不对称性。     

离心铝热法

离心铝热法离心铝热法可用来对管内侧施加涂层。首先把氧化铁和铝的混合物放置在管子的内侧，然后高速旋转对混合物产生离心力。这时，利用乙炔火焰引燃混合物，反应快速蔓延而产生铁和ＡＩ。Ｏ。；由于二者的密度不同，其混合物就分层了，形成人ｌ。Ｏ。表面层和铁内层。...     

A flexible automated foam cutting system

Direct cutting of foam has the advantage of greater flexibility and reduced lead time over molding. This paper discusses the design and development of a flexible automated system for foam cutting that utilizes hot-wire cutters. The cutters are moved through the use of a five-axis gantry-type robot system equipped with a tool turret. A method for modeling the cut geometry, based on representing the three-dimensional cut shape as a combination of basic geometrical block shapes, is presented. This method gives the system flexibility to handle different workpiece geometries. A technique for generating the required cutting paths from the modeled geometry is also shown. The developed methodology was applied for the cutting of automotive seat cushions. The results show that the automated system significantly reduces the cutting time and produces cuts of improved quality.     

排列管电极电解切割加工技术研究

采用微细铜管排列组成具有任意待加工形状的电极,可进行高效率、低成本的切割加工。对排列管电极电解加工过程进行了建模仿真,对电解加工过程机理的研究具有一定参考价值。采用排列管电极加工出深度分别为100、200 mm的圆弧形及"V"形切缝,加工过程稳定,无火花短路现象发生。大深度试件的成功切割证明了排列管电极电解切割加工技术的可行性。     

激光诱导前向转移中传输过程对银浆薄膜均匀度影响研究北大核心

激光诱导太阳能正面电极化过程中,银浆薄膜的运输方式和速度都会对最终形成的栅线形貌产生影响。为合理设计机械转运装置,针对规模印刷中直线运输和环形运输两种典型转运方式,建立简化的银浆薄膜有限元模型,并使其在一定加速度下运动,探究银浆薄膜的自愈特性;在3种不同转运速度曲线下(线性加速,指数形加速,S形加速)对银浆薄膜均匀度进行仿真实验。结果表明:在相同的速度下,由于离心力的存在,环形运输方式所导致的均匀度变化比直线运输方式更严重;在直线运输中,最大速度较低时,薄膜在3种速度曲线下的变形程度相似;随着速度增大,薄膜在线性加速曲线下的变形最小,并且指数形加速和S形加速都出现了银浆溅出的情况。在印刷光伏硅片正面栅线时,对银浆薄膜进行线性加速下的直线运输能保持其较好均匀性。     

复合地层中不同刃形滚刀与岩石接触行为研究

目的 滚刀截面形状即刃形对滚刀综合性能影响显著,研究不同刃形的滚刀在复合地层中的载荷变化特点,把握各型滚刀应用于复合地层时的优势与劣势,对于减少滚刀失效、降低刀盘偏载具有重要指导意义。方法 通过滚刀破岩试验获取和对比3种刃形的滚刀(平顶、圆顶和螺旋槽滚刀)在软硬复合地层中的切削力、破岩体积等关键指标,同时建立滚刀破岩有限元数值模型,探究滚刀刃形影响其切削岩石性能的机理和规律。结果 在复合地层中工作时,平顶滚刀所需的法向力均值最高,其余滚刀则相近。这是由于圆顶和螺旋槽滚刀破岩时仅有部分表面参与接触,接触面积均小于平顶滚刀,应力集中效应明显,从而降低破岩法向力。螺旋槽滚刀在切削不同强度岩石时的法向力差距最小;圆顶滚刀的法向力标准差的值最小。3种滚刀均形成了粉末状和片状岩石碎片,平顶和圆顶滚刀形成的岩石碎片总体积相近而螺旋槽滚刀略低。结论 复合地层软硬岩强度相差较大时,可选用螺旋槽滚刀以减轻刀盘偏载;硬岩部分强度较高时,推荐选用圆顶滚刀,以减小切削力和载荷冲击。     

Cutting capacity of PDC cutters in very hard rock

An experimental programm of investigating the cutting capacity of PDC flat cutters in very hard rock has been performed, Experiments include both the cutting of PDC fixed at different angles on the granite core or bar and linear cutting with different static thrust on the block of granite, The effects of the rough degree of rock surface, cutting angles,and static thrust on the cutting capacity of PDC in very l‘mrd rock were investigated and analyzed. The results show that the single modp of rotarv drilling llsing PDC cutterg is not annlied fnr very hard rocks.     

离心式滚磨光整加工钛合金的数值模拟分析

目的研究离心式滚磨光整加工对钛合金表层残余应力场的影响。方法利用有限元分析软件ABAQUS建立了加工过程中磨块碰撞TC4钛合金材料的三维有限元模型,对碰撞过程中的能量变化、材料应变及不同光整参数对工件表面残余应力场分布规律的影响进行分析,对比碳化硅磨块与氧化铝的加工效果。结果磨块参数对残余压应力峰值影响显著,但对其出现的位置影响不大。与碳化硅磨块相比,氧化铝磨块更适合于加工钛合金。结论有限元模拟可以探讨磨块碰撞作用下钛合金材料残余应力场的分布规律,优化滚磨光整加工钛合金的工艺参数。碰撞模拟证明,氧化铝磨块更适用于钛合金材料的滚磨光整加工。     

Development of automatic variable preload device for spindle bearing by using centrifugal force

Machine tool spindles of late require high stiffness and fast rotation characteristics all at once for high-speed, high-efficient processing, as well as for a wide range of use rotation. As such, many studies are being carried out on automatic variable preload control methods that apply a preload to a spindle rolling bearing as an alternative to the existing fixed position preload and constant pressure preload methods. This paper introduces a newly structured automatic variable preload device that can automatically adjust the preload applied to spindles employing a rolling bearing. It proposes an automatic variable preload device with a completely new composition comprising of a main bearing to which the preload is applied, an auxiliary bearing that conveys the force and a centrifugal element that converts the centrifugal force into a force in the axial direction, and a constant pressure preload spring that applies the initial preload to the main bearing. Other changes in the centrifugal force are also presented. The proposed composition was validated through a contact nonlinear analysis, and the design data necessary to create a prototype were obtained. A prototype for the automatic variable preload device using centrifugal force was then created and tested to confirm that the preload device of the proposed structure runs properly and smoothly.     

大口径厚壁钢管热模法离心铸造机的设计与应用

详细介绍了采用热模法离心铸造厚壁钢管坯的设计思路,以及该机主要机构(等量浇注装置、主机、推管机构等)的设计.     

Peripheral milling conditions for improved dimensional accuracy

Peripheral milling with flexible helical cutters is analyzed and modelled. The end mill is modelled as a cantilevered beam clamped to the collet with linear springs. Cutting forces and resulting tool deflection marks on the surface are analytically expressed. It is shown that by proper selection of cutting conditions, the material removal rate can be increased significantly without sacrificing the dimensional accuracy of the finished product. A method of identifying optimal feedrate and width of cut for given cutter dimensions and cutting constants is presented with experimental verification.     

A fuzzy expert system for the design of machining operations

In this paper, a fuzzy expert system called Smart Assistant to Machinist, or SAM, is introduced. The system consists of four modules: a database, a cutter selection module, a cutting condition design module and a learning module. The database consists of four data files: work material data file, machine tool data file, machining plan data file (which defines desirable material removal rate, surface finish, cutting speed, feed, depth of cut, etc.) and cutter data file. The cutter selection module is developed based on fuzzy logic, in which the cutter selection is conducted in three steps. First, the input information is “fuzzyized” Next, using the fuzzy correlation functions, cutter grades and cutters are selected. Then, the selected grades and cutters are searched against the cutter data file to check the availability. The cutting condition design module is developed based on fuzzy non-linear programming and user interactive graphics. The learning module is developed so that users can fine-tune the fuzzy functions to further improve the performance of the system. The system has two distinct features: (1) it can select cutters and design cutting conditions based on partial and imprecise information, and (2) it selects commercial cutter products used on shop floors. The use of the system is demonstrated using two examples.