Y.Z. Lan
,
S. Zhang
金属学报(英文版)
Based on the characteristics of graphite ore from Panzhihua district, the present research tried to find a new technology to increase the purity of the graphite carbon from 93% to 97%. Study was conducted on leaching agents, time, temperature, stirring speed and concentration of leaching solution affecting the process. The technological parameters chosen were: L / S=3:1, reaction time 30min, 5% concentration of sulfuric acid, reaction temperature 70℃, stirring speed 200rev/min. The results of the continuing tests with one kilogram showed that the graphite content can be increased from 93% to 97%, which reaches the requirement for high grade graphite. When waste acid from coke making is used to leach graphite, the result is also satisfactory, but the treatment of waste solution containing organic substances has to be further investigated.
关键词:
graphite ore
,
ore
,
High
,
grade
,
Chemical
,
metho
Ling ZHENG
,
Yinong LI
材料科学技术（英文）
Graphite/TiO¬2 composite particles were obtained by sol-gel technique in this paper. The structure and characteristic of the composite particles are analyzed by XRD, SEM and TG-DTA. The electrorheological properties of the ER fluid containing the particles were measured by a Couette-type rheometer under shear rates of 1～136 s-1 and AC electric fields of 0～3 kV/mm. The experimental results show that the leaking current density of the ER fluid is higher than that of pure titanium dioxide particles dispersed in damping oil. The shear yield stress of the ER fluid increases with increasing electric field and exhibits a typical Bingham flow behavior. The suspension demonstrates an excellent ER performance (τ/τ0=1200) compared with conventional ER fluids (τ/τ0≤500). The sedimentation of the ER fluid is improved obviously due to the coating effect of the particles.
关键词:
Electrorheological fluid
,
null
,
null
,
null
,
null
Shu LI
金属学报(英文版)
Silver matrix composite brushes were fabricated by means of powder metallurgy, which included pressing at 300 MPa and then sintering for 1 h in pure H2 protective atmosphere at 700 ℃ and repressing at 500 MPa. Four kinds composites with different compositions were produced, and the mechanical properties and electrical wear performance were investigated. The results showed that the composite added with carbon nanotubes had a higher hardness and strength, a lower contact voltage drop and an excellent anti-wear property in electrical sliding wear, because of the reinforcement ability of carbon nanotubes. Adding graphite to the composite also decreased the wear loss and contact voltage drop, because graphite had an electrical current conducting ability which not only made the current pass the lubricating films easily but also eliminated and reduced the arc and spark effectively.
关键词:
Ag-MoS2 composite
,
Carbon nanotube
,
Graphite
,
Electrical contact
,
Wear voltage loss
Mustafa Boz
,
Adem Kurt
,
null
,
null
材料科学技术（英文）
Iron powders were mixed with graphite powders by 1~15 wt pct to produce block samples using powder metallurgy technique. The powders were blended in a three dimensional blender for 20 min and compacted in a die under 500 MPa by using a one directional press. Sinterability and mechanical properties of the samples with different carbon content were investigated. Sintering process was carried out on a belt furnace with flame curtain in dissociated ammonia atmosphere. Block samples produced were suitable for ASTM B-312 transverse rupture strength test apparatus and were tested with 0.050 kN/s velocity in a press under 100 g load. It was found that graphite amount up to 2 wt pct increased the contact area of particles and acted as a lubricant to affect the sintering behaviour positively. The results indicated that the samples containing up to 5 wt pct showed good sintering behaviour and also good hardness due to an increase in pearlite amount. However, the samples containing higher amount of graphite (more than 5 wt pct) affected the sintering behaviour negatively due to the settlement of free graphite around the Fe powders, which resulted in a decrease in the hardness and transverse rupture strength.
关键词:
Powder metallurgy
,
null
,
null
,
null
,
null
新型炭材料
应用半经验分子轨道计算绝对速率理论,研究了乙烯和丙烯碳酸酯(EC,PC)分解的反应机理,推断了丙烯碳酸酯在石墨阳极上反常分解行为.还原出来的自由基的二次聚合反应,被认为是这一速率的决定因素.PC的二聚速率远慢于EC,这就导致PC的反常分解行为.
关键词:
电池用炭
,
石墨
,
电化学性质
,
MOPAC
江行国
,
程晓华
,
文华
,
柳永宁
新型炭材料
以固体废弃物兰炭焦末为原料,通过硼( B)掺杂及高温处理制备出改性兰炭粉末材料。研究B掺杂量对其作为锂离子电池负极材料的影响。结果表明,B掺杂质量分数为8%时,经2300益高温处理,兰炭的电化学性能达到最佳,首次脱锂容量为361 mAh/g,在1 C电流密度下经300次循环后,容量为314 mAh/g,表现出较为优良的循环性能。
关键词:
锂离子电池负极材料
,
石墨
,
兰炭
,
掺杂
,
热处理
曹宗良
,
王健农
,
丁冬雁
,
戴杰华
,
余帆
新型炭材料
doi:10.3969/j.issn.1007-8827.2003.01.009
利用化学气相沉积法,采用二甲苯为碳源,二茂铁为催化剂,氮气作保护气,在石英基底上催化裂解生长定向纳米碳管.试验结果表明:在775℃、120min的条件下,可生长出长达200μm厚的定向纳米碳管薄膜;在775℃,反应时间为60min～120min时,纳米碳管的长度为100μm～200μm,而纳米碳管的直径变化不明显.而无氢气、较高的反应温度和连续的催化剂供给对快速生长定向纳米碳管有着重要的影响.
关键词:
纳米碳管
,
石墨
,
催化剂
,
化学气相沉积
徐世江
新型炭材料
doi:10.3969/j.issn.1007-8827.1999.04.001
石墨是最古老的一种堆芯材料,是核时代的助产士.CM是高温气冷堆(HTR)堆芯的基础材料,它与陶瓷核燃料及氦冷却剂一起赋予HTR以冷却剂出口温度高、固有安全性好的优越发特性.CM在HTR中的工作条件恶劣,特别是高温和强辐照.文中介绍了炭素材料(CM)在核工程中的应用,给出了对核工程用CM的要求,同时评述了国际上CM的研究和发展工作及取得的成就,指出了进一步发展的方向.
关键词:
石墨
,
热解碳
,
高温气冷堆
,
包覆燃料颗料
,
慢化剂
,
辐射效应
