TC4钛合金人工关节的精密锻造

根据人工关节零件的技术条件要求，确定了其精密模锻的工艺方案。在1600t曲柄压力机上利用机械压力机恒载荷精锻方法成功地实现了TC4钛合金人工关节的精密锻造，锻件符合YY0117．1－93外科植入物骨关节假体锻、铸件（TC4钛合金锻件）标准。     

柴油机连杆采用自动辊锻制坯工艺的技术经济效果

连杆的锻造工艺有热模锻压力机锻造、摩擦压力机锻造和锤上模锻等几种。锤锻连杆一般在锻模上设拔长和滚压模膛制坯,热模锻压力机锻造连杆多用辊锻机制坯,摩擦压力机锻造连杆以空气锤制坯居多,少部分以辊锻机制坯。在大批量锻造连杆时,辊锻机制坯和空气锤制坯相比有较好的技术经济效果。本文以应用实例作以介绍。     

高能螺旋压力机锻造线上465Q曲轴成形技术开发及应用

曲轴是发动机的关键零件,随着发动机技术要求的提高,曲轴铸改锻趋势日趋明显。锻造曲轴需要大型的锻造设备,如大吨位的模锻锤,重型热模锻压力机,大规格高能螺旋压力机等。介绍以25000kN离合器式高能螺旋压力机为模锻主机的曲轴锻造生产线上465Q曲轴的锻造工艺与模具设计,包括工艺流程的确定,25000kN离合器式螺旋压力机模架和锻造模具设计,4000kN切边压力机上切边模具的设计,4000kN摩擦压力机上热校正模具的设计,最后介绍所设计各种模具的应用效果。     

模锻省力的原理与途径

模锻是塑性成形所需载荷最大的工序,随着锻件材料强度不断提高与尺寸的加大,所需锻造载荷也不断加大。前苏联于1967年建成世界上最大的750 MN模锻液压机并投产,同年美国也提出建造2 000 MN巨型模锻压力机的建议,对该拟建的压力机及其制造难度进行描述。从理论上阐明影响模锻变形力的因素及模锻省力的思路,指明减低模压时材料的流动应力,以及减少飞边处的单位压力可以显著减低变形载荷。并指明20世纪70年代由美国发明的等温锻与超塑锻可十分有效地减低流动应力,使现有压机的设备吨位能满足更强材料、更大尺寸工件成形的新要求。因而淡化对2 000 MN模锻液压机建造的迫切性。以前梁模锻为例,由于采用精确辊锻制坯减少终锻飞边体积成功地实现了用25 MN高能螺旋压力机生产出与120 MN楔式压力机相同规格前梁锻件,说明省力成形的重要性。     

万吨线翻番增长 大型模锻件竞争加速入红海

一、6条万吨线支撑“百万重卡” 2000年前,国内万吨级以上锻造生产线只有3条,分别是一汽锻造厂的125MN热模锻压力机生产线、东风锻造厂的120MN热模锻压力机生产线和湖北神力锻造厂的125MN热模锻压力机生产线。2008年,一汽巴勒特锻造（长春）有限公司和第一拖拉机股份有限公司锻造分公司的125MN热模锻压力机生产线分别建成投产,     

离合器外壳闭式模锻工艺设计

以2500t电动螺旋压力机应用为背景,针对锻件离合器外壳成形时金属流动困难、打不靠、充不满等技术问题,通过在外形、拔模斜度、锻造余块、过渡圆弧和机加余量等方面进行分析,优化锻造工艺及模具设计,突破了小吨位设备精密成型大型复杂锻件的窄口,形成了独具特色的"以小搏大"的闭式精密模锻技术。掌握了锻件成形过程精确控制、可靠性模具设计等关键技术,实现了复杂锻件的精确成形,并应用于批量生产,取代了普通模锻工艺。     

圆钢精密剪切模

目前,国内汽车、拖拉机、船用机械等行业中的部分齿轮,已广泛采用精密模锻工艺生产。但由于对齿轮的坯料精度要求较高,一般剪切工艺又达不到生产要求。因此不得不采用落后的锯切落料工艺,但生产效率低,材料浪费多,重量误差大. 后来,我们研制了一副圆钢精密剪切模,安装在JA31-160B闭式单点压力机上落料。经使用,证明坯料质量好,技术经济效果显著。     

小四轮半轴连接法兰盘锤上无飞边模锻

无飞边模锻(闭式模锻)比开式模锻节省10%～20%的飞边材料,是一种先进节材的锻造工艺。目前国内的闭式模锻(精锻),多采用精密下料或毛坯少无氧化加热,使用压力机等带顶出器的锻造设备来实现的。而锤上无飞边模锻并不多见。下面介绍我厂在锤上无飞边的模锻工艺及模具设计。     

HFP型温热模锻造压力机滑块机构设计

本文介绍了HFP系列温热模锻压力机的滑块机构的结构及特点，及其与其它锻压机械冲头不同的独特设计形式，体现了该温热模锻造压力机刚性好、稳定性高、高速高效等特点。     

国产离合器式螺旋压力机及其在锻造生产线中的应用

螺旋压力机的基本形式有摩擦压力机、电动螺旋压力机、液压螺旋压力机和离合器式螺旋压力机等，其中摩擦压力机历史最长。摩擦压力机制造容易，价格低廉，作为锻锤的替代产品，在国内中小型锻造企业得到了广泛应用。青岛锻压机械厂20世纪80年代通过引进德国Hasenckver公司的摩擦压力机技术而提升了摩擦压力机的制造水平。但摩擦压力机的控制可靠性和安全性差，效率低，其摩擦传动结构不适合大型化，在国外已经很少生产。随着国内锻造技术的发展和锻件质量要求的不断提高，锻压设备也面临换代和升级。目前国产锻压设备中，引进德国Eumuco公司技术生产的系列热模锻压力机和离合器式螺旋压力机(或简称高能螺旋压力机)都是在选用锻造设备中值得优先考虑的。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.