65Mn2SiVTi钢连续冷却转变的研究

用Ｆｏｒｍａｓｔｏｒ－Ｆ型全自动相变仪，金相显微镜和扫描电子显微镜研究了６５Ｍｎ２ＳｉＶＴｉ钢过冷奥氏体的转变动力学曲线及转变产物的组织，结果表明，６５Ｍｎ２ＳｉＶＴｉ钢不析出珠光体组织的临界冷却速度为１．３℃／ｓ，在０．１～０．５℃／ｓ冷却速度范围内可获得细片状珠光体。     

不同冷却速度下球墨铸铁的基体组织

采用Ｇｌｅｅｂｌｅ１５０００试验机研究了不同冷却速度下球墨铸铁的基体组织,研究结果表明,对于成分（％）为３．６２℃,３．０３Ｓｉ,２．５１Ｍｎ,０．０２Ｓ,０．０３Ｐ的球墨铸铁,冷却速度小于０．０２５℃／ｓ,其基体组织为铁素体和球光体;当冷却速度为０．２－０．５℃／ｓ时,基体组织主要为珠光体;当冷却速度为１－６℃／ｓ时,基体组织为贝氏体和马氏体;当冷却速度提高１５℃／ｓ时,基体组织全部为马氏体组织     

贝氏体型非调质钢过冷奥氏体的连续冷却转变

研究了一种 Ｍｎ Ｂ系低碳贝氏体型非调质钢过冷奥氏体的连续冷却转变,获得了试验用钢过冷奥氏体的连续冷却转变曲线。试验结果表明,本试验用钢过冷奥氏体不发生先共析铁素体析出的临界冷却速度为０．７℃／ｓ;冷却速度在１～４．５℃／ｓ 范围内可得到全部贝氏体组织;当冷速大于４．５℃／ｓ 时,不再有贝氏体生成,室温组织为马氏体和残余奥氏体。     

86CrMoV7钢热变形奥氏体CCT图

采用膨胀法测定了８６ＣｒＭｏＶ７钢经Ｔ＝９００℃，ζ＝１ｓ＾－１，ε＝０．４热变形后的连续冷却变曲线。结果表明，试验用钢在连续冷却转变过程中，只存在珠光体，马氏体转变，不发生珠光体转变的临办冷却速度为３．１℃／ｓ，Ｍｓ点为１５０℃，组织分析发现，未溶碳化物可成为珠光体转变的核心，促进珠光体转变。     

9Cr-1Mo-V-Nb-N钢高温变形规律的研究

利用Ｇｌｅｅｂｌｅ－１５００热模拟试验机,研究了９Ｃｒ－１Ｍｏ－Ｖ－Ｎｂ－Ｎ铁素体耐热钢在８５０～１２５０℃,变形速率０．０１～１０ｓ－１的变形条件下的再结晶行为。获得了９Ｃｒ－１Ｍｏ－Ｖ－Ｎｂ－Ｎ钢热变形时发生动态再结晶的边界条件,作出了塑性图和再结晶图。     

快凝合金Zr（Ni0.55Mn0.3V0.1Cr0.05）2.1的相结构与储氢性能

在快冷（冷却速度１０＾５－１０＾６Ｋ／ｓ）Ｚｒ（Ｎｉ０．５５Ｍｎ０．３Ｖ０．１Ｃｒ０．０５）２．１合金中观察到一种高温条件下丰碑 纳米晶Ｃ１４Ｌａｖｅｓ相,其丰度随冷凝速度下降明显减少。     

34CrNi3Mo钢高温变形行为与Zener－Hollomon因子的关系

通过热模拟压缩试验，研究了３４ＣｒＮｉ３Ｍｏ合金结构钢在温度８４０～１２００℃，变形速度０．１～８０Ｓ~（－１）变形条件下的热压缩行为。获得了３４ＣｒＮｉ３Ｍｏ钢的变形激活能及峰值流动应力（σ_ｐ）、发生动态再结晶的临界条件（包括临界因子Ｚ_ｃ和临界应变ε_ｃ）和再结晶晶粒大小（ｄ）与Ｚｅｎｅｒ－Ｈｏｌｌｏｍｏｎ因子Ｚ的关系，并给出了回归公式。     

热处理工艺对3Cr-1Mo-0.25V-Ti-B钢组织与性能的影响

采用光学金相、透射电镜（ＴＥＭ）、Ｘ射线衍射分析（ＸＲＤ）和力学性能测试等方面研究了处理工艺对３Ｃｒ－１Ｍｏ－０．２５Ｖ－Ｔｉ－Ｂ钢组织与性能的影响。试验结果表明，该钢在空冷条件下可获得均匀的粒状态贝氏组织，具有良好的耐回火性和较高综合力学性能。同时，给出了最佳热处理工艺。     

高强钢应力腐蚀门槛值随强度的变化规律

恒位移试样测量表明,４０ＣｒＭｏ钢在３．５％ＮａＣｌ水溶液中应力腐蚀（ＳＣＣ）门槛应力强度因子ＫＩＳＣＣ随屈服强度σｓ指数下降、即ＫＩＳＣＣ＝１．３８×１０６ｅｘｐ（－８．２６×１０－３σｓ）．动态充氢时氢致开裂（ＨＩＣ）门槛应力强度因子ＫＩＨ随试样中可扩散氢浓度Ｃ０（１０－６）的对数而线性下降,即ＫＩＨ＝３１．１－９．１１ｎＣ０． ＳＣＣ时也遵循这个规律．发生ＨＩＣ型ＳＣＣ的临界氢浓度Ｃｔｈ随σｓ指数下降,从而可导出ＫＩＳＣＣ＝ａｋ１ｅｘｐ（－ｋ２σｓ）;其中ａ＝３ＲＴ　／２（１＋ν）ＶＨ,ＲＴ是热能,ρ是裂纹止裂时的曲率半径,ＶＨ是氢在钢中的偏摩尔体积,ν为Ｐｏｉｓｓｉｏｎ比,ｋ１和ｋ２则是和成分及组织有关的常数．     

冷却速度对Fv520（B）多马氏体组织的影响

利用膨胀法、金相、ＸＲＤ法研究了冷地ＦＶ５２０（Ｂ）钢Ｍｓ点及其组织的影响。结果表明，ＦＶ５２０（Ｂ）钢具有良好的淬透性，其Ｍｓ点为１５５℃，冷和速度降低，Ｍｓ点略有升高。在冷却速度为１７．５℃／ｓ～０．０３℃／ｓ的范围内，均得到马氏体组织，冷却速度对马氏体组织状态影响不大。     

球形LiNi1/3Co1/3Mn1/3O2的合成及其电化学性能

以化学共沉淀法制备的球形Ni1/3Co1/3Mn1/3CO3为前驱体合成了球形LiNi1/3Co1/3Mn1/3O2,研究LiNi1/3Co1/3Mn1/3O2合成工艺对产物形貌的影响.结果表明直接以前驱体Ni1/3Co1/3Mn1/3CO3与Li2CO3反应合成的LiNi1/3Co1/3Mn1/3O2的一次颗粒较大,以前驱体分解后的氧化物与Li2CO3反应合成的LiNi1/3Co1/3Mn1/3O2的一次颗粒相对细小;合成的LiNi1/3Co1/3Mn1/3O2均为具有层状结构的纯相物质;球形正极材料LiNi1/3Co1/3Mn1/3O2充放电过程中存在一个材料活化的过程,在前10周期充放电时,电池容量处于增加的状态;在2.7～4.3 V的电压范围内1 C倍率下电池的放电比容量达到149 mA·h/g,0.2 C倍率下为158 mA·h/g,经50次循环后容量无衰减.     

不同金属离子价态的前驱体制备球形LiNi1/3Mn1/3Co1/3O2的性能比较

利用共沉淀法和控制结晶氧化法在不同条件下分别制备出低价态球形Ni1/3Co1/3Mn1/3(OH)2和高价态球形Ni1/3Co1/3Mn1/3OOH前驱体,并分别和LiOH·H2O在不同温度烧结合成出球形锂离子正极材料Li(Ni1/3Co1/3Mn1/3)O2.XPS分析表明,制备的高价态球形Ni1/3Co1/3Mn1/3OOH前驱体其过渡金属Ni、Co和Mn的价态分别是2+,3+,4+,XRD分析表明,高价态球形Ni1/3Co1/3Mn1/3OOH前驱体比低价态球形Ni1/3Co1/3Mn1/3(OH)2前驱体具有较高的活性,能够在低温下合成出Li(Ni1/3Co1/3Mn1/3)O2,而且制备的产物结晶度高,阳离子混排程度小,具有规整的层状a-NaFeO2结构.充放电实验表明,由高价态球形Ni1/3Co1/3Mn1/3OOH前驱体制备的Li(Ni1/3Col/3Mn1/3)O2具有优良的充放电性能和循环性能.     

Li(Mn1/3Ni1/3Co1/3)1-yMyO2(M=Al,Mg,Ti)正极材料的制备及性能

采用液相共沉淀合成锰镍钴氢氧化物前驱体, 在前驱体中掺入元素M(M=Al, Mg, Ti), 与锂结合生成Li(Mn1/3Ni1/3Co1/3)0.98M0.02O2材料, 结果表明掺杂可有效提高材料的循环性能. X射线衍射结果表明 随掺钛量增大(0≤y≤0.15), 晶格畸变增大, 半高宽变大, 晶粒粒径增大; 其中掺钛量y=0.1的材料电化学性能表现最好, 以20 mA/g电流充放电, 在2.5～4.6 V电压区首次放电容量可达215 mA·h/g.     

Synthesis of LiNi1/3CO1/3Mn1/3O2 cathode material via oxalate precursor

Using oxalic acid and stoichiometrically mixed solution of NiCl2, CoCl2, and MnCl2 as starting materials, the triple oxalate precursor of nickel, cobalt, and manganese was synthesized by liquid-phase co-precipitation method. And then the LiNi1/3Co1/3Mn1/3O2 cathode materials for Li-ion battery were prepared from the precursor and LiOH-H2O by solid-state reaction. The precursor and LiNi1/3Co1/3Mn1/3O2 were characterized by chemical analysis, XRD, EDX, SEM and TG-DTA. The results show that the composition of precursor is Ni1/3Co1/3Mn1/3C2O4·2H2O. The product LiNi1/3Co1/3Mn1/3O2, in which nickel, cobalt and manganese are uniformly distributed, is well crystallized with a-NaFeO2 layered structure. Sintering temperature has a remarkable influence on the electrochemical performance of obtained samples. LiNi1/3Co1/3Mn1/3O2 synthesized at 900 ℃ has the best electrochemical properties. At 0.1C rate, its first specific discharge capacity is 159.7 mA·h/g in the voltage range of 2.75-4.30 V and 196.9 mA·h/g in the voltage range of 2.75-4.50 V; at 2C rate, its specific discharge capacity is 121.8 mA·h/g and still 119.7 mA·h/g after 40 cycles. The capacity retention ratio is 98.27%.     

正极材料Li（Ni1／3Co1／3-xMn1／3）MxO2（M=Ti，Mg）的合成及性能

采用草酸盐前驱体合成Ti4+、Mg2+掺杂正极材料Li(Ni1/3Co1/3-xMn1/3)MxO2(M=Ti, Mg).利用XRD和SEM对其结构和形貌进行表征,并采用循环伏安、交流阻抗、恒流/恒压充放电测试其电化学性能.结果表明:Ti4+、Mg2+掺杂后晶胞体积增大,大倍率充放电时LiNi1/3Co1/3Mn1/3O2的电化学反应阻抗Rct降低,其大倍率充放电性能得到改善,Ti4+掺杂效果更好;当掺杂量x＝0.025时,材料晶型完整,具有单一的a-NaFeO2层状结构;1C倍率时Li(Ni1/3Co1/3-0.025Mn1/3)Ti0.025O2的第二循环放电容量为143.2 mA-h/g,2C时为128.0 mA-h/g,经100次循环后容量分别为132.5和115.8 mA-h/g,容量保持率为92.53%和90.47%.     

锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2的制备及性能研究

采用溶胶-凝胶法制备了锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2,并考察了烧结温度对材料结构、表面形貌和电化学性能的影响.XRD和SEM测试结果表明,900℃下烧结得到的样品是粒径在0.3～0.5 μm范围的球形粒子,具有最佳的阳离子有序度;充放电测试结果表明,其在0.1C倍率下首次放电容量达到148.8...     

Preparation of LiNi1/3Co1/3Mn1/3O2 cathode materials from spent Li-ion batteries

A recycling process including separation of electrode materials by ultrasonic treatment, acid leaching, Fe-removing, precipitation of cobalt, nickel, manganese and lithium has been applied successfully to recycle spent lithium-ion batteries and to synthesize LiNi1/3Co1/3Mn1/3O2. When ultrasonic treatment with 2-nitroso-4-methylphenol（NMP） at 40 ℃ for 15 min, the electrode materials are separated completely. Above 99% of Co, Ni, Mn and Li, 95% of Fe in the separated electrodes are acid-leached in the optimized conditions of 2 mol/L H2SO4, 1：2 H2O2：H2SO4 （molar ratio）, 70 ℃, 1：10 initial S：L ratio, and l h. 99.5% of Fe and less than 1% of Co, Ni, Mn in the leaching solution can be removed in the conditions of initial pH value 2.0-2.5 adjusted by adding 18% Na2CO3, 90 ℃ and stirring time 3 h. After adjusted to be equal by adding NiSO4, COSO4 and MnSO4 solution, 97.1% of Ni, Co, Mn in the Fe-removing surplus leaching solution can be recovered as Ni1/3Co1/3Mn1/3（OH）2. 94.5% of Li in the surplus filtrate after the deposition of Co, Ni and Mn can be recovered as LiECO3. The LiNi1/3Co1/3Mnl/3O2, prepared from the recovered compounds, is found to have good characteristics of the layered structure and elecrtochemical performance.     

锂离子电池正极材料LiNi_1/3Co_1/3Mn_1/3O_2的研究进展

介绍了一种新型的锂离子电池正极材料LiNi1/3Co1／3Mn1／3O2的最新研究状况,描述了材料的晶体及电子结构,以及电化学性能;重点总结了现今国内外制备此材料的几种主要合成方法及研究进展;同时,介绍了不同掺杂元素（Fe、B、Al、Ti）对材料的改性作用。     

Zn掺杂对LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2结构与电化学性能的影响

用溶胶凝胶法制备了Li Ni1/3Co1/3-x Mn1/3Znx O2(x=0,1/24,2/24,4/24)锂离子电池正极材料。由X射线衍射和扫描电镜对其分析结果表明,Zn掺杂不改变Li Ni1/3Co1/3Mn1/3O2的α-Na Fe O2层状结构,当掺杂量达到4/24时,杂相产生。电化学研究表明,当Zn掺杂量为2/24时,Li Ni1/3Co1/3Mn1/3O2首次放电容量由未掺杂的169.2 m Ah·g-1降低为160.1m Ah·g-1,但循环性能明显提高,30次循环后的容量保持率由未掺杂的89.2%升至97%。并且在20、40、60和80 m A·g-1不同的电流密度下继续循环20次后,当再次恢复到20 m A·g-1的电流密度时,放电容量可恢复到150.3 m Ah·g-1。     

Effect of calcination temperature on characteristics of LiNi1/3Co1/3Mn1/3O2 cathode for lithium ion batteries

LiNi1/3Co1/3Mn1/3O2 was synthesized by sol-gel method and effect of calcination temperature on characteristics of LiNi1/3Co1/3Mn1/3O2 cathode was investigated. The structure and characteristics of LiNi1/3Co1/3Mn1/3O2 were determined by XRD, SEM and electrochemical measurements. The results show that the compound LiNi1/3Co1/3Mn1/3O2 has layered structure with hexagonal lattice. With the increase of calcination temperature, the basicity of the material decreases, and the size of primary particle rises. The LiNi1/3Co1/3Mn1/3O2 calcined at 900 ℃ for 12 h shows excellent electrochemical performances with large reversible specific capacity of 157.5 mA-h/g in the voltage range of 2.75-4.30 V and good capacity retention of 94.03% after 20 charge/discharge cycles. Capacity of LiNi1/3Co1/3Mn1/3O2 increases with enhancement of charge voltage limit, and specific discharge capacities of 179.4 mA.h/g, 203.1 mA.h/g are observed when the charge voltages limit are fixed at 4.50 V and 4.70 V, respectively.