运用刀具在线监控技术优化汽轮机轮槽刀具寿命

通过刀具在线监控技术监控分析汽轮机轮槽铣刀在切削加工镍基高温合金中的状态,研究刀具在切削加工中的磨损规律,得出优化刀具寿命的可行性方法,以提高刀具的切削寿命。试验结果表明,通过调整刀具的切削参数可提高刀具的切削寿命。     

钛合金材料的铣削刀具磨损试验研究

通过TC11铣削加工时的刀具寿命试验,研究了钛合金铣削时影响刀具磨损的几个因素,为提高刀具寿命优化了刀具参数.同时通过刀具磨损试验,了解刀具的磨损机理和提高刀具的寿命.     

在钛合金零件上实现高效钻削的方法

介绍了在钛合金零件上实现高效钻削的方法。以某航空零件为例,从刀具材料、刀具特点、切削参数、加工中应注意的问题等多个方面介绍了在钛合金材料上进行孔加工的经验,所介绍的孔加工刀具和方法对加工效率的提高和刀具寿命的延长都具有很大的优势,对于钛合金的高速切削技术有一定的参考意义。     

基于镍基高温合金加工工艺的研究与应用

通过对气相质谱分析仪中镍基高温合金Inconel625零件（离子源腔体）的切削加工工艺的分析研究,以及通过对不同切削刀具（涂层刀具CVD＆PVD）的性能研究和参数的组合试验,验证并总结出了合理有效的工艺方案,攻克了加工难点并卓有成效地达到延长刀具寿命和设计目标,又降低了制造成本。     

枪钻加工20CrMnTiH时切削性能的改进

枪钻在加工20CrMnTiH材料时存在断屑难、排屑难导致刀具磨损、寿命降低等主要问题。本文对实际加工条件和被加工材料的特点进行分析后,修改了钻尖的几何参数来进行改进。经过一系列试验研究证明,改进后的枪钻解决了实际加工中断屑难、排屑难的问题,并使刀具寿命提高了两倍。     

高温合金零件切削加工工艺研究与应用

通过对气相质谱分析仪中镍基高温合金Inconel625零件(离子源腔体)的切削加工工艺的分析研究,以及通过对不同切削刀具(涂层刀具CVD & PVD)的性能研究和参数的组合试验,验证并总结出了合理有效的工艺方案,攻克了加工难点并卓有成效地达到设计目标,延长了刀具寿命,降低了制造成本.     

智能刀具的选择

<正>刀具技术的革新发展是提高数控加工技术的重要条件。传统的刀具技术革新主要涵盖刀具几何结构的更新设计,使用更先进的刀具材料以及采用更合理的加工方式来提高刀具寿命,实现更高的加工精度并提高工艺可靠性。得益于互联网技术的发展,金属切削技术也进入到全新的数字化时代。     

粉末冶金零件加工研究进展

介绍了国内外粉末冶金烧结件加工的研究现状,对工艺参数优化、刀具磨损、已加工表面质量进行了详细分析,阐述了改善粉末冶金烧结件可加工性的措施:表面浸渗、添加易切削剂。分析了粉末冶金生坯加工时工艺参数对已加工表面质量的影响、生坯强度的提高以及生坯加工后的烧结件的力学性能。     

SiC_p/Al复合材料复杂曲面的精密加工刀具设计

针对高体积分数SiC_p/Al复合材料复杂曲面难加工问题,设计了一种四刃PCD球头立铣刀。首先分析了SiC_p/Al材料性能和工件结构,得到刀具设计要求;其次通过对刀具和工件材料的对比分析,确定了刀具材料为PCD材料以及刀片参数;再次综合实验数据和金属切削原理,优化设计了刀具的基本几何参数,建立了刀具模型;最后进行了新刀具的加工实验,结果表明:设计的球头立铣刀提高了铣削加工性能,有效增加了刀具寿命,可为SiC_p/Al复合材料在航空航天等领域的推广使用提供借鉴。     

高效切削铁基高温合金刀具磨损特性研究

传统刀具磨损评估标准并以其确定的刀具寿命有一定的局限性,不适用于不同几何角度和不同切削参数下刀具耐磨损性能的比较。本文以刀具磨损新特性—表面磨损率理论为基础,研究了车削铁基高温合金GH2132的刀具磨损特性,得出了最小表面磨损率和所对应的最佳切削速度及温度,为进一步研究加工该高温合金材料在优选刀具和切削参数,提高刀具寿命以及生产效率等方面提供了理论基础。     

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.     

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....     

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.     

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.