钛合金的深孔钻削技术研究

钛合金的切削加工性能差,其深孔钻削的技术难度更大。枪钻是深孔钻削的高效刀具,能有效解决钛合金的深孔加工问题。本文基于对钛合金材料切削性能和深孔钻削工艺的分析,通过深孔钻削试验,改进了钛合金叶片深孔钻削工艺,提高了枪钻寿命。     

钛合金材料深孔钻削工艺研究

钛合金的切削加工性能差，尤其是钻削深孔的技术难度更大。这里通过对钛合金材料的切削性能和深孔钻削工艺的研究，设计出了一种专门用于钻削钛合金的深孔钻头，并通过一系列钻削试验表明，其工艺效果良好，有效地解决了钛合金材料的深孔钻削。     

不锈钢和钛合金工件的高效深孔钻削工艺

针对不锈钢、钛合金材料的深孔加工问题 ,分析了难加工材料的切削特性。从刀具设计及工艺方面 ,对高效深孔钻削进行了研究 ,并实际进行了切削试验 ,取得了较为满意的加工效果     

钛合金深孔钻削温度测量及加工表面质量研究

深孔加工技术广泛应用于航空航天领域,钛合金由于其难加工性对深孔加工提出了巨大挑战.提出了一种基于麻花钻深孔钻削钛合金的在线温度测量方法.通过全因素实验,分析了钛合金加工表面质量和加工硬化现象.试验结果表明切削速度对钻削温度有很大影响,当切削速度过大时,表面质量迅速恶化,产生表面烧伤和严重的加工硬化现象,进给速度对钻削温度略有影响.综合分析后推荐用于干切削条件下TC4钛合金深孔钻削的切削参数为20m/min,0.08mm/rev.     

钛合金深孔钻削钻头刀片材料和几何参数的选择

这里以难加工材料钛合金为研究对象，针对钛合金材料的加工难点特性，选择目前国内相应的硬质合金材料，并优化组合出不同的钻头几何参数，进行了深孔钻削试验。通过对试验结果进行分析，确定出适合加工钛合金材料的深孔钻用刀片材料和几何参数。     

钛合金深孔钻削刀具的研究

针对钛合金材料的难加工特性，选择了几种目前国内常用的硬质合金材料，并优化选择不同的钻头几何参数，进行了深孔钻削试验，通过对试验结果进行分析，确定出适合加工钛合金材料的深孔钻用刀片材料和几何参数。     

钛合金深孔钻削刀具的试验研究

以钛合金深孔钻削刀具为研究对象,针对钛合金材料的难加工特性,选择了几种常用的硬质合金刀片材料,并优化选择不同的刀片几何参数,进行了深孔钻削试验。通过分析试验结果,确定出适合加工钛合金材料的深孔钻用刀片材料为YT726,其磨损特性优于其他刀片材料,钻削47.4mm钛合金深孔时,比较合理的刀片几何参数为前角γo=7°、后角αo=12°、余偏角ψr=15°、钻头偏心量e=3.8mm。     

钛合金小直径深孔的钻削加工

<正> 钛合金的比强度大,韧性高,但其回弹量大,导热性差,因而切削性能下降,特别是小直径深孔钻削加工更为困难。本文仅从我厂的实际情况出发,就钛合金小直径深孔钻削在刀具材料的选择、切削用量及刀具几何角度的选配和切削液的选用等方面进行了初步试验和实践。1.钛合金在钻削加工中的特点钻孔时切削状况沿整个切削刃是变化的,对于普通麻花钻,由于钻头的前角由外圆向钻心逐渐减小,切削状况由里向外逐渐改善,而在横刃处的工件材料要承受     

超细长小直径深孔的加工工艺研究

针对不锈钢及钛合金材料的超细长小直径深孔零件,从工件材料和切削性能以及小直径深孔零件的加工方法和刀具等几方面进行论述,并具体分析了两种零件的加工工艺过程及加工效果。     

小直径精密深孔钻削机理的试验研究

本文以45~#钢φ8DF深孔钻削系统为研究对象,利用回归分析与正交设计的方法,通过对大量试验数据的处理。研究了小直径深孔钻削中切削参数对切屑容屑系数、加工精度和表面粗糙度的影响。得出了适用于中碳钢小直径精密深孔钻削的一系列重要结论。     

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...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.