制备工艺对Cu/C滑动电接触材料组织与性能的影响

本文研究了固相烧结、液相烧结、烧结熔渗和热压烧结等几种工艺制备Cu/C复合材料,并测试它们的显微组织、密度、硬度和电导率,结果表明:四种工艺碳都呈网状均匀分布在基体上,熔渗和热压工艺制备的Cu/ C复合材料密度和硬度最高,而固相烧结的较差,电性能几种制备工艺差别不大。     

冷压成型方向对W-Cu电触头材料性能的影响

针对轴向、径向两种压制方向成型的W—Cu合金,采用烧结熔渗法制备W—Cu／Cu整体电触头材料,测定结合面的抗拉强度及W—Cu合金的电性能、显微组织和抗弯强度。结果表明,轴向压制产品烧结后的结合强度远大于径向压制产品烧结后的结合强度。W—Cu合金的物理性能也是轴向压制的比径向压制的好,但两种压制方法对材料的抗弯强度影响不大。     

小型断路器用AgWNi触头材料的研制

采用粉末冶金熔渗工艺制备AgWNi触头材料,研究了材料的烧结行为以及添加元素Ni对材料性能的影响。用Archimede法测量样品密度,并对材料的显微组织进行了分析。结果表明,Ni可有效改善Ag与W的润湿性,使材料获得较高的致密度。与AgW55材料相比,其相对密度可达到98%~99%(提高约1.23%),硬度提高14.48%,电阻率降低3.9%。     

CuW/Cu整体触头气孔缺陷的消除

研制了CuW/Cu整体触头的加工工艺,同时探讨改善熔渗质量、消除熔渗气孔的方法,并对采用不同工艺制造CuW/Cu整体触头在性能和显微组织上作了对比分析。结果表明:采用氢气保护熔渗,并真空除气工艺研制的CuW/Cu整体触头密度达到理论密度的99％～100％,硬度、电阻率达到和超过国外相关标准规定的技术指标。在空气断路器、SF_6断路器上得到使用,能满足使用要求。     

骨架制备工艺对熔渗法AgW(65)触头材料金相组织和性能的影响

采用熔渗法制备AgW(65)触头材料,对不同骨架制备工艺获得的AgW(65)触头材料的金相组织和性能进行了比较,分析了骨架制备工艺对材料金相组织和性能的影响。结果表明,采用纯W骨架坯制备的触头材料具有良好的综合性能,其具有金相组织均匀、密度高、电阻率低、硬度高的特点。     

激光增材制造钨铜复合材料

钨-铜(W-Cu)复合材料综合了W和Cu一系列优良特性,如高硬度、高强度、良好的热电性能、较低的热膨胀系数以及较强的抗电弧烧蚀性能等,在电子工业、军工国防、航空航天等领域有广阔的应用和发展前景。然而,采用传统的粉末冶金、熔渗法等制备方法难以制备出高致密、高性能且具有复杂结构的W-Cu复合材料。增材制造技术的出现为解决上述问题提供了难得的契机,本研究采用此技术制备W(25)Cu复合材料,通过优化激光功率和扫描速率等加工参数,获得最佳工艺参数组合。利用该组合工艺参数成型的W-Cu复合材料表面平整,密度为11.78 g·cm-3,显微硬度平均值达到320 HV,硬度分布较为平稳,层间结合良好,热膨胀系数为7.33×10-6·K-1,导热系数为56 W·m-1·K-1,性能较好,并且微观组织均匀。     

钨铜材料的热等静压处理

研究了钨铜材料的热等静压处理。试验材料为W—Cu40。热等静压前,它是通过混合、压制成型,预烧结和熔渗铜制得。热等静压在低于铜的熔点和90—100MPa压力下进行。测定了热等静压前后坯料和试样的密度、硬度、抗弯强度和导电率。证明,热等静压可使W—Cu40坯料的密度从12.7—12.8g/cm~3达到13.2—13.3g/cm~3,接近完全致密化,它消除了熔渗状态的缩孔、疏松和熔渗不良等缺陷,从而提高和改善了硬度、强度和导电度等性能,试验亦表明,W—Cu20材料的热等静压亦有良好效果。     

熔渗法AgW（75）触头材料研究

电触头作为电器设备的关键元件之一,既是载流体,又是机械零部件,要求具有良好的导电导热性、耐电孤烧损、抗熔焊、低而稳定的接触电阻、有一定的强度和易于机械加工等。本研究采用粉末冶金熔渗技术制备AgW（75）电触头材料,对其进行复压、复烧,并测量了其力学物理性能和显微组织。结果表明,粉末冶金熔渗技术与复压复烧相结合制备的AgW（75）触头材料的相对密度高,硬度达到国家标准要求,但材料收缩性大。     

共沉积法AgFe2O3电接触材料的组织与性能研究

采用共沉积工艺制备了AgFe2O3电接触材料。用X射线衍射、金相显微镜等观察了材料的相组成及显微组织,测量了材料的密度、硬度、电导率等性能。结果表明,采用共沉积工艺制备的AgFe2O3电接触材料组织均匀,电阻率为2．1μΩ．cm,密度为9．6g／cm^3。     

H2气氛熔渗CuW触头材料性能的研究

重点研究了H2气氛熔渗方法制造的高压开关Cuw触头材料的物理机械性能,分析了影响材料性能的因素。测试了材料的密度、硬度、电导率、抗弯强度、抗拉强度、延伸率和冲击韧性,结果显示：H2气氛熔渗Cuw触头材料具有良好的物理机械性能,符合GB／T8320、ASTM B702标准和用户对Cuw触头的性能要求。特别是Cuw70合金具有较好的综合性能,能够满足高压开关GIS的技术要求。金相组织分析和对断口形貌的扫描电镜分析发现,H2气氛熔渗的Cuw触头材料金相组织均匀致密、孔隙少、无夹杂物,W颗粒大小分布均匀并被Cu均匀包覆。相对密度高、金相组织均匀、孔隙少、无夹杂物是H2气氛熔渗Cuw触头材料性能良好的主要原因。     

水雾化法AgSnO2（12）粉末压坯烧结工艺探讨

摘要：采用水雾化法制备掺杂Bi、Cu元素的AgSn合金粉末,氧化后在不同单位成型压力条件下成型,然后在马弗炉中分别于880、900、920℃下烧结2、4、6h,考察了单位成型压力、烧结温度和烧结时间对材料致密度和硬度的影响。结果表明,提高单位成型压力和烧结温度、增加烧结时间可以提高材料的致密度和硬度。     

Study on preparation of CNTs-Cu composites materials by chemical coprecipitation hydrogen reduction solid state sintering process

The CNTs-CuO composite powders were synthesized by chemical co-precipitation method, when the co-precipitation temperature was set as 70°C, stirring rate was set to 1000 rpm, pH was 10, drip reaction time was 120 min and the drying temperature was 50°C. Carbon nanotubes (CNTs), Copper sulfate, sodium hydroxide were used as raw materials. 8%CNTs-Cu and 16%CNTs-Cu composite powders were synthesized by hydrogen reduction, reduced at 300°C for 2h. 8%CNTs-Cu composite bulk were prepared by a solid-phase sintering process when the molding temperature was 800°C, while 16%CNTs-Cu composite bulk cannot be prepared by the same method.     

W/Cu和Mo/Cu复合材料组织与性能的对比分析

本文采用粉末冶金法对W／Cu和Mo/Cu材料进行了系统研究。结果表明,W／Cu和Mo/Cu材料的制备工艺、组织结构类似,前者的硬度、密度和热导率较后者的高;而后者的电导率高于前者。故不同的应用场合应选择不同的复合材料。     

WC/Cu大电流滑动电接触材料的研究

为了提高电接触材料的导电、导热等性能,笔者采用粉末冶金溶渗技术制备出WC/Cu滑动电接触材料,并对其显微组织和性能进行了系统研究。结果表明:WC60～90/Cu滑动电接触材料随着WC含量的增加,材料的密度由11.508 g/cm3增加到13.305 g/cm3,硬度由HB187增加到HB477,导电率由14.6 m/(Ω.mm2)下降到10.6 m/(Ω.mm2)。耐磨性随着WC含量的增加显著提高,但高Cu含量的孕育期较长。磨损机制以磨粒磨损和表面接触疲劳为主。建议使用含量为WC70/Cu30～WC80/Cu20的滑动电接触材料。     

Study on Cu/ZrW2O8 composite layers prepared by co-electrodeposition

ABSTRACT

To obtain composite materials with a low coefficient of thermal expansion (CTE), Cu/ZrW₂O₈ composite layers were prepared by co-electrodeposition. The influence of the co-electrodeposition parameters on the particle content in the composite layers and the effects of particle content on the thermal expansion and microhardness of the layers were studied. In general, the addition of ZrW₂O₈ particles significantly enhanced the microhardness and reduced the CTE of the Cu/ZrW₂O₈ composite materials. The surface morphology changed with the current density and ZrW₂O₈ particle loading. Finally, the CTE of the Cu/ZrW₂O₈ composite materials was much lower than that of pure Cu.     

Y2O3/La2O3/Al2O3/Cu复合材料的制备与性能

采用含氧氮气(N2/O2)雾化喷射沉积技术制备Y-La-Al-Cu系多元系合金,通过化学反应原位生成(内氧化法)Y2O3/La2O3/Al2O3/Cu多相氧化物颗粒增强铜基复合材料,并对材料的显微组织、力学物理性能和电学性能进行研究。结果表明,通过喷射沉积技术并结合内氧化工艺,可制得具有较好微观组织、形成的增强相弥散分布于基体、组织致密的Y2O3/La2O3/Al2O3/Cu多相氧化颗粒增强铜基复合材料;随着冷加工变形量的增加,Y2O3/La2O3/Al2O3/Cu多相氧化颗粒增强铜基复合材料的抗拉强度和硬度提高,而材料的延伸率与导电率逐渐降低。     

Uniformly Dispersed Nano-SiO2 Particles Reinforced Copper Matrix by Chemical Coprecipitation Method

Abstract

Nano-Cu-based materials have many applications in the microelectronics and aerospace industries, which not only maintain the advantages of copper materials, but also make up for the shortage of copper. In this paper, the precursor powder of silica-reinforced copper matrix composites was prepared by chemical coprecipitation method, which main ingredients are Cu₄SO₄(OH)₆ and SiO₂. The precursor powder was reduced by hydrogen in 450?°C for 4?h to obtain SiO₂-Cu composite powder, and then treated by cold press pressing and solid phase high temperature sintering to obtain nano-silica copper matrix composite. The results show that that the reinforcing phase and matrix are mutually dispersed in the process of coprecipitation, and the composite gains more homogeneous size and higher hardness as the dispersion effect of reinforcement on the copper matrix achieves the best.     

溶胶凝胶法制备Li_4Ti_5O_(12)/C负极材料及电化学性能

采用溶胶凝胶法,以有机物钛酸四丁酯和醋酸锂为原料,草酸为螯合剂,PEG为碳源制备出Li_4Ti_5O_(12)/C复合材料前驱体,在N_2气氛中850℃高温煅烧制备出Li_4Ti_5O_(12)/C复合材料。通过XRD、SEM分析表明,850℃下煅烧10 h合成结晶性良好的亚微米级纯相尖晶石钛酸锂。电化学性能测试结果表明,Li_4Ti_5O_(12)/C在0.2C,1C,2C倍率下的首次放电比容量分别为173.3、168.7、166.3 mAh/g。与Li_4Ti_5O_(12)相比,显示出良好的倍率性。     

硫化铜微球电化学储锂性能研究

以硝酸铜[Cu(NO3)2·3H2O]和硫代乙酰胺(TAA)为原料,通过溶剂热法制备中空球状结构硫化铜。研究了中空微球样品作为锂离子电池负极材料的电化学性能。讨论了焙烧温度和焙烧时间等条件对硫化铜样品的物相结构和电化学性能的影响。研究发现,焙烧后的硫化铜样品的电化学性能表现良好,在0.1 C电流密度下首次充放电比容量均超过了理论比容量(560 m Ah/g),其中焙烧温度为150℃、焙烧时间为1 h的硫化铜样品,其首次放电比容量达到682.8 m Ah/g,且循环25次后其比容量仍能保持在106.7 m Ah/g,表现出了良好的循环稳定性。     

The relation of trap distribution of alumina with surface flashover performance in vacuum

Alumina ceramic samples prepared under different sintering temperatures and varied additives were measured to indicate the trap density and trap energy located in alumina materials by using thermally stimulated current (TSC). The surface charges on alumina in vacuum after applying a negative pulse voltage (0.7/4 /spl mu/s), and flashover performances of the materials in vacuum also were measured. We found that the trap distribution in alumina has a correlation with surface charges and flashover performances in vacuum. It is shown that the higher is the trap density in the material, the higher is the surface charge density, and the lower is the flashover voltage on alumina surface. It is believed that the trapping and de-trapping mechanisms of carriers could play an important role during the development of the discharge processes, together with the secondary electron emission mechanism.