齿槽等分性对时栅位移传感器的精度影响分析

时栅位移传感器主要采用线切割加工的工艺手段实现产品定子和转子的齿槽加工.线切割加工的精度受限于机床自身精度、钼丝实时补偿能力和切削液纯净度等诸多因素,齿槽等分性精度在一定程度上影响着传感器的最终精度.提出采用精密插齿工艺制备时栅位移传感器,以克服线切割加工齿槽等分性差的问题,并通过开展齿槽等分性对比试验和精度实验进行了齿槽等分性对时栅位移传感器精度影响的分析.实验表明采用插齿工艺的传感器其误差曲线对极间一致性更好,而且误差较同等参数线切割下的减小20％左右.     

齿槽等分性对时栅位移传感器的精度影响分析（英文）

时栅位移传感器主要采用线切割加工的工艺手段实现产品定子和转子的齿槽加工。线切割加工的精度受限于机床自身精度、钼丝实时补偿能力和切削液纯净度等诸多因素,齿槽等分性精度在一定程度上影响着传感器的最终精度。提出采用精密插齿工艺制备时栅位移传感器,以克服线切割加工齿槽等分性差的问题,并通过开展齿槽等分性对比试验和精度实验进行了齿槽等分性对时栅位移传感器精度影响的分析。实验表明采用插齿工艺的传感器其误差曲线对极间一致性更好,而且误差较同等参数线切割下的减小20%左右。     

光栅位移传感器在位置伺服系统中的应用及误差分析

介绍了光栅位移传感器的原理和特点及其在闭环位置伺服系统中的应用,对于位置伺服系统的系统误差作了理论分析.利用光栅位移传感器对位置伺服系统进行了动态测量和控制.结果表明,光栅位移传感器精度高,稳定性好,不接触、无磨损、抗干扰能力强,输出信号大.     

一种基于VB的超声波线切割机导轨误差的测量与补偿系统设计

以机床导轨误差理论为基础,基于VB设计了一种机床导轨误差测量与补偿系统。该系统采用光栅传感器来确定导轨的水平位置,通过电涡流位移传感器把被测量(机床导轨误差)转化成电信号,用USB2828数据采集卡的AD功能把传感器输出的电信号转化成数字信号,按传感器及驱动电源的灵敏度计算出补偿误差所需的电压值,再用采集卡的DA功能输出电信号给驱动电源。驱动电源的输出电压控制微位移器的位移(即刀尖的位移)变化,实现了导轨误差的补偿。实验结果表明测试系统的设计较合理,基本达到了补偿的要求。     

直线时栅位移传感器正交激励信号源设计

时栅激励信号质量直接影响时栅磁场运动匀速性,进而决定时栅位移测量精度,因而研究高精度时栅激励信号源对于提高时栅传感器测量精度具有重要意义。针对直线时栅传感器对正交激励信号高质量的要求,采用直接频率合成技术设计满足要求的正交激励信号源。并且设计了一种有源带通滤波器用来消除干扰,提高信号质量。设计的正交激励信号具有幅值和频率可任意调节,并且具有精度较高,设计简单方便的特点。通过FPGA芯片将时栅传感器激励信号源与信号处理电路的一体化设计,最大限度地缩小时栅信号处理电路体积,并提高工作可靠性。仿真和实验结果证明了设计的有效性。这种设计方法可广泛应用于许多需要高质量激励信号的应用场合。     

三点法传感器误差分析及一种改良方法

为了减小传感器定位对测量结果的影响和传感器拆装麻烦以及传感器多问题,提出了一种改进的三点法。该方法通过简化模型,计算出传感器的定位误差、倾斜度误差、错位误差的测量误差值,比较传感器不同方向的误差计算值,结合高精度旋转刻度盘和光栅尺,对测量结构进行改善。实验结果表明,该方法能够正确分离工件的形状误差和回转误差,测量误差能够达到±0.05μm,测量重复性好,能够减小工件的检测成本和安装时间。     

直线时栅位移传感器正交激励信号源设计（英文）

时栅激励信号质量直接影响时栅磁场运动匀速性,进而决定时栅位移测量精度,因而研究高精度时栅激励信号源对于提高时栅传感器测量精度具有重要意义。针对直线时栅传感器对正交激励信号高质量的要求,采用直接频率合成技术设计满足要求的正交激励信号源。并且设计了一种有源带通滤波器用来消除干扰,提高信号质量。设计的正交激励信号具有幅值和频率可任意调节,并且具有精度较高,设计简单方便的特点。通过FPGA芯片将时栅传感器激励信号源与信号处理电路的一体化设计,最大限度地缩小时栅信号处理电路体积,并提高工作可靠性。仿真和实验结果证明了设计的有效性。这种设计方法可广泛应用于许多需要高质量激励信号的应用场合。     

价格下降 服务更周全 质量有保证——威勤公司力争3年内占领中国球栅尺市场的一半份额

球栅尺是一种新颖的位移动态传感器,它采用电感测量原理,具有抗干扰、抗振动、抗污染和可靠耐用等优点。目前球栅尺在国际上已被普及推广应用于各种模具及机械加工行业中,1996年开始。该项技术在我国首次成功地应用于液体流量校准装置的精确位移动态测量上。     

一种测试锻压机械运动参数的新方法

锻压机械运动速度、位移的测量方法很多,如测速电机法、定距测时法,光栅法、电阻应变片法、镦铅柱法等等。这些方法有的可用于测速,有的可用于测位移,有些属直接测量,有些属间接测量,但是,既可用于精确测速,同时又可精确测量位移的方法尚不多见,尤其是动态下的精确测量更不多见。为解决此问题,我们自行研制了一种动态磁栅式传感器,该传感器不同于静态磁栅式传感器,它既可测速又可同时测量位移,为测量工作提供了极大的方便。经不断改进,目前该传感器位移分辨率达0.05mm,测量速度误差<2％。经在不同场合应用,效果非常好。     

一种薄型化的直线式时栅位移传感器研究

传统直线时栅位移传感器存在机械结构加工效率低和线圈绕线一致性差的缺点,且无法满足一些应用场合在厚度方面的需求,因而文章结合电磁感应式直线时栅传感器的工作原理,开展了一种薄型化直线时栅位移传感器的研究。该传感器通过结合PCB工艺技术将传感单元印制在电路板上对传统结构进行改进,实现薄型化的设计。通过传感器模型设计、仿真验证和精度实验,验证了传感器的可行性。实验结果表明:在0~280mm的测量范围内,传感器样机的原始测量误差在±30μm之间。该传感器的实现,可以为直线时栅传感器在薄型化方向的研究提供重要借鉴。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。