高纯氮气流雾化制备粉状镍基焊料的研究

采用高纯氮气流雾化法制备低熔点镍基焊料,探讨了雾化气体类型、熔液温度、流速及雾化压力等因素对镍基粉末钎料的氧含量、粉末形状及粉末粒度的影响.结果表明:高纯氮气流雾化工艺制备的镍基粉末钎料氧含量为0.014%～0.018%,在熔液流量4 kg/min、雾化气体压力3.0 MPa及雾化熔液温度1230 ℃的条件下,制取的粉末满足了不锈钢用钎料的钎焊技术性能要求.     

镍焊膏的制备

以镍基合金为原料,高纯氮气为雾化气体,在合适的熔体温度、熔体漏速和雾化气体压力下,可制备出球形度好、氧含量0.014%、粒度约70μm的镍钎料粉末.以工业白油和聚合物为成膏体制备的镍焊膏,其焊接质量达到了国标要求.     

一种焊膏用铝基钎料粉末的制备

采用真空熔炼、惰性气体雾化的工艺生产焊膏用铝基钎料(AS-1)粉末.在雾化压力1.2 MPa、熔液流量3.0 kg/min和熔液温度780℃的工艺条件下,所制备的钎料粉末粒度小于0.15 mm的质量分数大于85%,其中0.045～0.15 mm粉末占成品粉质量分数90%以上,粉末呈球形.所制备的钎料粉末达到了铝焊膏用钎料的性能.     

一种焊膏用铝基钎料粉末的制备

采用真空熔炼、惰性气体雾化的工艺生产焊膏用铝基钎料（AS-1）粉末.在雾化压力1.2 MPa、熔液流量3.0 kg/min和熔液温度780℃的工艺条件下,所制备的钎料粉末粒度小于0.15 mm的质量分数大于85%,其中0.045~0.15 mm粉末占成品粉质量分数90%以上,粉末呈球形.所制备的钎料粉末达到了铝焊膏用钎料的性能.     

气雾化制备Al-Si钎料粉末的研究

针对铝/不锈钢大面积钎焊对钎料的特殊要求,采用气雾化法制备了Al-Si共晶合金钎料粉末,并对雾化金属熔体质量流率、雾化气体压力及雾化温度等影响雾化效果的主要因素进行了研究.结果表明,在金属液流直径dt=5 mm,雾化气体压力P=1.0 MPa,雾化温度720～770℃的条件下,可制备出75～350μm粉末的质量分数达90%以上的钎料,其各项性能指标均达到法国同类产品的水平.     

气雾化制备Al-Si钎料粉末的研究

针对铝/不锈钢大面积钎焊对钎料的特殊要求,采用气雾化法制备了Al-Si共晶合金钎料粉末,并对雾化金属熔体质量流率、雾化气体压力及雾化温度等影响雾化效果的主要因素进行了研究.结果表明,在金属液流直径dt=5 mm,雾化气体压力P=1.0 MPa,雾化温度720～770℃的条件下,可制备出75～350μm粉末的质量分数达90%以上的钎料,其各项性能指标均达到法国同类产品的水平.     

锌基中温钎料的研究

采用氮气气流雾化法制备锌基钎料粉末,研究了在锌基钎料中添加Cu,Si及Be元素对锌基钎料熔化温度、抗拉强度和流动性的影响.当w(Zn)=76.62%,w(Al)=19.16%,w(Si)=1.2%,w(Cu)=3.0%,w(Be)=0.2%时,锌基钎料的熔化温度约为480℃、抗拉强度为126 MPa及铺展面积为2.2 cm2.     

王思鸿1,文 艺2*,卜永周1,张淑婷2,罗良良1,李 航2,孙军刚1,洪瑞平1

AgCuTi合金钎料成分是影响其性能的重要因素。本文采用熔炼雾化法制备了不同组分的AgCuTi钎料粉末,对粉末的氧含量、熔点、微观组织及硬度进行了测试与表征,并基于数理统计中的二次多项式回归方法和交互作用关系,利用JMP软件建立了各元素含量对AgCuTi合金钎料熔点影响的数学模型,通过回归拟合定量描述了各元素含量与熔点的变化关系。研究结果表明,Ti含量是影响AgCuTi活性钎料粉末熔点及硬度的最显著因素,当Ti含量为2~4.6 wt.%时,钎料熔点随Ti含量的增加而升高,熔点最低约为780 ℃左右,最高为812℃左右,AgCuTi钎料硬度也随Ti含量的增加而增大,从122.79 HV增大到248.82 HV,增大了126.03 HV。本研究计算模型精度较高,可预测不同组分含量AgCuTi合金钎料的熔点,研究结果可为Ag-Cu-Ti体系合金钎料的选材应用提供参考。     

气雾化法制备3D打印用钴铬合金粉末工艺的研究

采用真空熔炼气雾化工艺制备3D打印用钴铬合金粉末,通过调整雾化工艺参数,研究了漏嘴直径、熔炼温度及雾化压力对粉末形貌、粒度分布、松装密度及流动性等特性的影响.结果表明:在熔炼温度为1670℃、雾化压力为5 MPa、漏嘴直径为5 mm的条件下,制备的合金粉末性能优异,平均粒径(D50)为30.70μm,松装密度为4.30g/cm~3,氧含量为0.032%,流动性为22.40s/(50g),可满足3D打印用钴铬金属粉末的性能要求.     

采用复合锌基钎料钎焊铜铝焊接接头的微观组织及力学性能

在Zn-27Al钎料表面电镀Ni制备复合锌基钎料,在氮气保护的电阻炉中用复合锌基钎料和Zn-27Al钎料对Cu与Al进行钎焊试验,运用金相显微镜、电子探针、X射线衍射仪分析了接头的微观组织,通过拉伸试验评定了接头的力学性能.结果表明:与未电镀镍层的Zn-27Al钎料钎缝相比,复合锌基钎料钎缝中没有组织偏聚,组织分布更均...     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

注浆加固技术在十三矿-685 m进风大巷中的应用

针对煤矿开采深度不断向深部延伸，掘进巷道受深部高应力的影响越来越大，巷道围岩整体稳定性差，矿山压力显现越剧烈现象，一般锚网喷加锚索支护无法从根本上控制巷道的变形。总结了平煤股份十三矿-685 m进风大巷注浆加固技术，依据对巷道掘进之后变形监测数据的采集，对巷道变形机理进行分析研究，并对注浆时段进行了合理选择，在对巷道的注浆工艺进行了充分论证的基础上，对巷道进行了注浆。注浆后效果表明:巷道滞后注浆时间段的选择非常重要，巷道在恰当的时间内进行注浆加固施工，能有效控制巷道的变形，巷道注浆后变形量明显减小，岩体的稳定性明显增强，减少了巷道日常维修工作，降低了矿井的生产成本，保障了矿井的安全生产。     

Brief news

正China Minmetals Rare Earth Construction of Jianghua Separation Plant is set to complete at the yearend Civil works of Jianghua Separation Plant have been finished and the company is installing and debugging equipments now.It is estimated that construction of Jianghua Separation Plant will be     

Brief news

正Total transactions of rare earth in Rare Earth Ex-change Center of Hunan South Rare and Precious Metal Exchange neared 40 billion yuan from January to October From the opening in January of this year to the end of October,the total transaction of rare earth products in Rare Earth Exchange Center of Hunan South Rare and Precious Metal Exchange neared40 billion yuan.There are 16 varieties including dysprosium oxide and terbium oxide traded on the exchange center,one of the largest trading platforms for rare earth oxides in China.     

Theoretical basis for optimal collector concentrations and pulp pH values during flotation of sulfide-free minerals

A hypothesis that associates optimal conditions of mineral flotation with a zero charge of their surface is put forward. This hypothesis serves as a basis for a methodology to obtain and verify quantitative physical-chemical models for a minimal necessary concentration of a collector during flotation of sulfide-free minerals. These models may be of use for upgrading engineering processes of flotation and as a job for the concentration plant automation systems. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 89–99, March–April, 2006.     

基于LPWAN技术的采煤沉陷区杆塔倾斜监测系统

随着地下采煤活动不断加大，越来越多的输电杆塔不可避免地被建设在煤矿沉陷区。目前，现有手段采用靠人力去进行定期检查一定会浪费大量的人力和物力，因而需开展对位于煤矿沉陷区的杆塔进行实时在线检测。基于NB-IoT和LoRa提出了一种新的算法——低功耗广域网（LPWAN）技术，提出了一种新型的输电杆塔倾斜监测系统，其中包含1个主节点和多个子节点，以适应地域广和远距离的需求信息监控。该系统通过LoRa多节点网络的数据传输，将杆塔的倾斜参数通过NB-IoT上传至在线实时监控系统。管理人员可以从后台得出监测数据并分析结果，及时对处于煤矿沉陷区的有故障的输电杆塔进行针对性的维护。     

矿井摩擦式提升机制动力补偿装置的设计

讨论了在煤矿提升机二级制动的基础上 ,对制动力矩进行补偿 ,保证提升机紧急制动时的减速度维持在《煤矿安全规程》规定的范围内。