New electrical steel with high permeability

This article describes the magnetic properties of a low-silicon-bearing nonoriented electrical steel, recently developed by UGINE S.A. as a core material for rotating machines. The new product is characterized by a high level of permeability related to a partial ideal texture {100}〈0vw〉. Typical properties are core losses of less than 5 W/kg at 1.5 T and 50 Hz and a magnetic polarization level greater than 1.78 T at 5000 A/m for a sheet thickness of 0.50 mm. The effects of sheet thickness and working induction on core loss at different frequencies are examined.     

复杂流道构件组合放电加工技术研究

复杂流道构件的高效、高精度加工是液体火箭发动机的核心制造技术之一,随着发动机涡轮泵功率及涡轮效率的不断提升,涡轮泵复杂流道构件的加工去除量大幅增加,同时对加工精度的要求也越来越严格。故提出了高速放电铣削粗加工与多轴联动电火花成形精密加工复合的加工工艺,通过对复杂流道构件的高速放电铣削加工电极损耗补偿和多轴联动电火花成形加工轨迹规划等技术的研究,实现了复杂流道构件的高效、高精度放电加工。     

数控插齿机在插削内型面方面上的应用研究

针对均布多边内方、多(或单)键槽等通常采用普通插床进行插削加工的内型面,由于插床精度低、插刀定位不准确,导致高精度的内型面尺寸和位置精度难保证、加工效率低等。根据数控插齿机工作原理及功能特点,用数控插齿机代替普通插床进行各种多内方、多(或单)键槽的插削加工。实践表明:数控插齿机插削内型面技术上可行,加工质量稳定可靠,技术成熟度高,效果十分理想,具有重要的推广应用价值。     

无压机分球式高压装置用复合传压介质的制备研究

以无压机分球式高压装置（BARS）制备宝石级金刚石时,对传压介质的相对密度要求很高。为提高传压效率,实验研究ZrO₂-NaCl复合传压介质的制备,分析其相对密度同密封效果、倒角设计的关系,并通过NaCl复合提高ZrO₂的传压性能。发现复合介质的传压效率比叶蜡石更高,但只有在相对密度92%时才能保证设备安全、稳定工作,且需加装密封边。最后,在自制BARS设备上使用ZrO₂-NaCl传压介质合成出2ct、VS级的黄色宝石级人造金刚石单晶。      

GH2036高温合金激光冲击强化后的残余应力

采用X射线衍射仪和材料试验机对激光冲击强化GH2036高温铁基合金的残余应力进行了研究.结果表明,激光诱导GH2036高温铁基合金的残余应力值和残余压应力层的深度随激光功率密度的增加而增加.激光强化件形成的残余应力在高温回火后有所松弛,但仍然保持较高的残余应力水平,一次回火后表面残余应力在-170 MPa,二次回火后残余应力仍然保持在-135 MPa.激光冲击强化件的疲劳寿命比未强化件的提高2.36倍以上.     

W-Cu复合材料制备新技术与发展前景

W-Cu复合材料具有热膨胀系数低、导电性好、导热性好、高熔点、高硬度以及良好的抗电弧烧蚀性能,在机械加工、电气工程以及电子信息领域被广泛用作电极材料、电接触材料、电子封装材料及靶材等越来越受到国内外的关注。传统粉末冶金方法制备的W-Cu复合材料致密度低、组织结构粗大且均匀性差,严重影响材料性能。采用纳米复合新技术制备的W-Cu复合材料具有很大的技术优势:粉末纳米化使得粉末的烧结活化能大大降低,其烧结活化能在1 420℃时仅为42.1 kJ/mol和29.1 kJ/mol,远低于纯W相同温度范围内的587.9 kJ/mol,同时纳米复合使得W与Cu发生了固溶,从而使得复合粉末表现出良好的烧结活性。采用纳米复合制备的细晶W-Cu复合材料具有非常优异的综合性能,其原因在于经烧结后获得高的致密度和组织结构均匀细小。     

Fabrication of a micro-pin array with high density and high hardness by combining mechanical peck-drilling and reverse-EDM

To fabricate circular cross-section micro-pin array with high hardness and high density in a fast and efficient way, a combined method of mechanical peck-drilling and reverse electrical discharge machining (reverse-EDM) is proposed in this research. First, a ball-cone-hole-magnet (BCHM) method is applied in high vibration cantilevered platform (HVCP) and quick release holder/jig to produce highly precise, fast and elastic positioning. Second, a micro-hole array with high density and different types of holes on a workpiece (brass material) is produced by a vibration-assisted mechanical peck-drilling (VAMPD), which includes the high vibration of workpiece created by HVCP and mechanical peck-drilling of micro-drill. This VAMPD can drill up to 1600 single-stage or multi-stage micro-holes, and the aspect ratio of the drilled one-stage micro-holes of Ø60 μm is up to ten. Finally, reverse-EDM is used to fabricate the micro-pin array made of tungsten carbide. In this process, the effects of the chip removal mechanism, the various micro-hole types, and the density of the micro-holes on the electrodes are investigated. The results indicate that the combination of multi-stage micro-hole electrodes and three chip removal methods (working fluid spraying, vibration-assisted electrode and shake-down type workpiece) can produce a 1600-micro-pin array with an average diameter below Ø30.00 μm, a length of 625.0 μm, and a pitch of 100 μm. Consequently, the proposed method of combining mechanical peck-drilling and reverse-EDM can fabricate a micro-pin array with high hardness, high density, high quantity, and uniform diameter in a fast and efficient way.     

影响铝熔体电磁净化效果因素的分析

从液态金属电磁净化技术的原理出发,在理论上分析了当夹杂物与金属熔体密度接近的情况下,可以利用两者之间的电性能与磁性能的差异来实现夹杂物的分离,达到金属熔体净化的效果。综述了影响电磁分离效率和效果的因素。表明在电磁净化过程中,通电时间越长、磁感应强度越大、管半径与集肤程度比值在1.5~2.0之间、分离管为异型管、夹杂颗粒越大且近于球形,分离效果越理想,分离效率越高。     

高频感应焊接逆变电源PWM和PFM软开关控制

高频感应焊接逆变电源具有体积小、效率高、加热速度快等优点,但是传统设备采用的是整流调压方式,其控制精度低、动态响应速度慢,并且逆变器功率开关管经常工作在硬开关状态,引起较大开关损耗,使效率降低.文中提出一种使用自关断器件绝缘栅极晶体管作为功率开关,采用脉冲宽度调节方式和脉冲频率调节方式混合调功方式的高频感应焊接逆变电源的软开关控制方法,详细分析了电路的控制原理和工作模式,并设计出以锁相环为核心的控制电路.结果表明,这种方法实现了全部开关器件的软开关控制,具有功率调节范围宽,软开关调整范围广的优点.     

一种含氟化镁电解质体系的温度、密度和导电度论证

本文对一种在生产中使用的含镁铝电解质体系的温度、密度、导电度利用经验公式进行了论证。通过论证得出如能通过技术手段和管理手段对电解质中各成份含量进行精细控制，电解生产可以在较低温度下高效运行；该电解质体系和铝液的密度差在一些情况下较小，生产中注意提前调控；该电解质体系和低分子比高氟化钙电解质体系的导电度相当。     

Some potential applications for intercalation compounds of graphite with high electrical conductivity

Intercalation compounds of graphite of the acceptor type have potential engineering applications because of their attractive electrical conductivity properties. Two kinds of applications are considered in this paper. The first concerns a composite, formed by enclosing an intercalation compound synthesized from high quality crystalline graphite in a matrix of copper. With this form of composite it is found that there are both intrinsic and extrinsic advantages pertaining to the use of a material that has a conductivity higher than and a density lower than that of copper. The second form is a composite compound of intercalated graphite fibers contained in a matrix of epoxy. Extraordinary advantages in this case result from the fact that while intercalation of the fibers produces an order of magnitude increase in their electrical conductivity, when these fibers are incorporated into an epoxy matrix, the composite conductivity is increased by two orders of magnitude over its pristine fiber counterpart. It is projected that these desirable electrical conductivity characteristics portend large scale uses for the acceptor compounds of graphite as substitutes for the present standard conductors, and as a way of upgrading the performance of carbon/graphite materials.     

数控龙门移动式高速镗铣床的直线同步进给传动

提出一种同步控制技术，将两个直线电机应用到龙门移动式高速镗铣床中，用直线电机带动龙门柱实现纵向进给，通过同步控制技术使两个龙门柱保持同步。本文在提出了设计思想之后，设计了应力补偿控制法，并给出具体实现手段，然后进行了仿真研究。     

Prospect of developing Nd-Fe-B-type magnet with high electrical resistivity

Nd-Fe-B-type magnet is exclusively used as a rotor magnet in the traction motor of hybrid electric vehicle(HEV) and electric vehicle(EV),but its overly high operating temperature is a lingering problem attached to the magnet.The major cause of the high operating temperature is eddy current,which is readily generated in the highly conductive metallic magnet under alternating magnetic field from stator ripple.In this article,temperature rise in the Nd-Fe-B-type magnet with varying electrical resistivity under alternating magnetic field is discussed with the intention of highlighting the importance of enhancing the electrical resistivity for reducing the operating temperature of the Nd-Fe-B-type rotor magnet.Temperature rise in the Nd-Fe-B-type magnet(dielectric salt-added die-upset magnet) with high electrical resistivity is noticeably lower compared to the magnet(commercial sintered rotor magnet) with lower electrical resistivity,substantiating the theory that enhancing the electrical resistivity in the rotor magnet is fairly effective for suppressing the over-rise of its operating temperature during operation.Die-upset process is revealed to be particularly pertinent for the fabrication of highly dense salt-added magnet with high electrical resistivity.     

高电流密度电解清洗带钢技术的分析研究

为了建设国内第1条高速高效的带钢电解清洗机组，对电解清洗机理、高电流密度电解清洗技术进行了研究探讨；分析了各种类型高密度电解清洗装置的优缺点及实例，为国内新建或同类机组改造选型提供了参考。     

QA35Y-30液压联合冲剪机的研制

开发了一种新型液压联合冲剪机QA35Y-30.该设备采用单缸结构,通过机械杠杆驱动冲压工作机构;采取单片机控制,可实现单次、连续、微动等冲压及剪切操作,并具有自动计数及预置等功能.剪切工作机构采用参数优化设计,在功率相同、结构简化的情况下,可剪切的最大方钢、圆钢、角钢等尺寸明显增加,一次剪切宽度可提高28.3%,机器的净重降低了1t,外形长度尺寸减小了400mm,减少率达到14.7%.QA35Y-30是高效率、低能耗的机、电、液一体化设备.     

日本内高压成形技术进展(英文)

文章回顾了自2003年于日本举行的第一届内高压成形国际会议(TUBEH YDRO2003)后该技术在日本的发展概况。近年来,铝合金热态内高压成形技术得到了较快的发展,利用该技术生产的汽车副车架试制成功,并已应用在轿车上;移动模具的出现提高了内高压胀形极限,使T形三通管制管的成形高度显著提高。文中还讨论了在内高压成形工艺优化、拼焊管内高压成形、锥形管内高压成形、高强钢管内高压成形、液压冲孔、成形极限图及内高压成形设备方面的进展。     

电火花穿孔机群孔加工路径规划算法

在使用电火花穿孔机进行自动化群孔加工时,电极需频繁地从前一个孔位移动到下一个孔位。当孔位较多时,累积的运动时间相当可观,导致整体加工效率降低。通过分析孔位的坐标和间距,基于旅行商问题近似解法和坐标排序,提出了几种有效且实用的群孔加工路径规划算法,并集成在穿孔机CAM软件中。测试结果表明,几种算法均能有效缩短孔位间移动的总体距离,从而提高了整体加工效率。     

Prospects for Non-Rare Earth Permanent Magnets for Traction Motors and Generators

With the advent of high-flux density permanent magnets based on rare earth elements such as neodymium (Nd) in the 1980s, permanent magnet-based electric machines had a clear performance and cost advantage over induction machines when weight and size were factors such as in hybrid electric vehicles and wind turbines. However, the advantages of the permanent magnet-based electric machines may be overshadowed by supply constraints and high prices of their key constituents, rare earth elements, which have seen nearly a 10-fold increase in price in the last 5?years and the imposition of export limits by the major producing country, China, since 2010. We outline the challenges, prospects, and pitfalls for several potential alloys that could replace Nd-based permanent magnets with more abundant and less strategically important elements.     

A new high shear degassing technology and mechanism for 7032 alloy

Degassing is very important for aluminum alloys especially for 7xxx series alloys.In the present study,a high shear technology was used to degas 7032 aluminum alloy in order to study its degassing efficiency.The experimental results showed that the high shear technology can significantly degas 7032 aluminum alloy.By applying intensive melt shearing and an Ar injection of 60 seconds,the density index,D_i,was reduced from13.25%to 0.28%and the hydrogen concentration was significantly reduced from 0.31 to 0.10 mL/100 g Al.Compared with the conventional rotary degassing,high shear technology showed a much higher degassing efficiency,achieving a lower concentration of hydrogen in a shorter time.The water simulation experiment was used to study the mechanism of the high degassing efficiency.The small bubble size and the uniform distribution of Ar bubbles with the application of high shear technology are believed to be the main cause for the high degassing efficiency.     

新一代信息化电焊机检测系统

对新一代信息化电焊机检测系统从结构、功能及其特点等方面进行了介绍。这种新型检测系统以虚拟仪器技术为实施平台．具有信息量大、检测速度快、人机界面优异、测量精度高、灵活性强等优点，同时实现了对孤焊电源谐波电流、动态特性的分析．以及功率因数、效率等重要参数的实时测量。