D.Wen 1)
,
Q.K.Cai 2)
,
C.S. Liu 1)
,
Y.J. Guo 1) and Y.H.Zhao 1) 1) School of Materials and Metallurgy
,
Northeastern University
,
Shenyang 110006
,
China 2) Shenyang University
,
Shenyang 110044
,
China
金属学报(英文版)
Laser surface alloying of γ TiAl alloy with nitrogen was studied under the constant protective nitrogen current (20l /min). The experimental results shown that the surface multi layers formed with experimental parameters could be up to 600μm depth; it consists of TiN,Ti 2AlN,α 2 and γ phases, without AlN, and the irregular coarse continuous “flow” line,dendrite,needle and granular nitrides disperse on the fine dendrite casting α 2 and γ phases substrate. The microstructure and compositions in the nitiding layer were determined and analyzed by SEM and EPMA and the mechanism for the formation of microstructure in the nitriding layer was also discussed.
关键词:
laser surface alloying
,
null
,
null
Acta Chimica Sinica
The stability of K2FeO4 in dilute KOH solution with initial pH value from 8.0 to 13.0 was studied in detail by spectrophotometry method in this paper. The decomposition rate of aqueous solution of K2FeO4 is basically regulated by its concentration, pH and the decomposed product FeOOH that can catalyze the decomposition of K2FeO4. The increase of HO- concentration can improve the stability of K2FeO4 by decreasing the collision frequency between FeO42- ions. However, when the concentration of HO- reaches a certain value, the decomposition product FeOOH is easily produced. FeOOH can catalyze the decomposition of K2FeO4. It was found that K2FeO4 is the most stable in the pH region of 10.0 similar to 11.0 and the decomposition rate of K2FeO4 is in the first order in the initial period. The decomposition rule of K2FeO4 along with its concentration in KOH solution is related with the initial pH of the solution.
关键词:
K2FeO4;stability;spectrophotometry method;electrochemical characteristics;ferrate(vi) ion;electrode;battery
任涛
,
梁益龙
,
刘国栋
,
王攀志
兵器材料科学与工程
doi:10.3969/j.issn.1004-244X.2012.03.003
研究60Si2CrVA弹簧钢经淬火-等温-淬火-回火(Q-I-Q-T)热处理后复相组织含量与断裂韧性间的关系.结果表明,在实验的等温温度范围内,随着等温温度的升高,残余奥氏体和贝氏体含量逐渐增大,60Si2CrVA钢强度降低,断裂韧性逐渐增加,在300℃等温时,断裂韧性达到最大值66.37 MPa·m1/2.稳定的残留奥氏体与过渡形态贝氏体量增加是提高断裂韧性的主要原因.
关键词:
60Si2CrVA
,
淬火
,
回火
,
马氏体
,
贝氏体
,
残留奥氏体
Journal of Physical Chemistry C
alpha-K(x)MnO(2) nanotubes with x = 0.10, 0.12, 0.15, and 0.17 have been synthesized through acid and alkali treatments of the precursor alpha-MnO(2) nanotubes. For the samples with x = 0.10 and 0.12, a large divergence of the ZFC and FC susceptibilities and pronounced hysteresis at low temperature are observed. However, the samples with x = 0.15 and 0.17 are antiferromagnetic with Neel temperatures of 25.4 and 25.3 K, respectively. The reciprocal susceptibility and electrical conductivity indicate that the samples with x = 0.15 and 0.17 undergo a charge separation transition from mixed/averaged valence state manganese ions to Mn(3+) and Mn(4+) between 250 and 300 K. Below half occupancy of the K(+) site (x <= 0.125), the strong geometrical frustration due to the triangular lattice configuration and the mixture of Mn(3+)/Mn(4+) result in the spin-glass behavior of the samples with x = 0.10 and 0.12. Above half occupancy of the K(+) site, the samples with x = 0.15 and 0.17 exhibit an antiferromagnetic feature due to the charge separation of Mn(3+) and Mn(4+). Our experiments display that the magnetic properties of alpha-K(x)MnO(2) can be tuned by varying the K(+) content.
关键词:
hydrothermal synthesis;manganese-dioxide;hollow urchins;tunnel;phase;transitions;nanowires;growth;oxides
姜奉华
,
徐德龙
硅酸盐通报
doi:10.3969/j.issn.1001-1625.2004.06.006
通过研究Q相与C2S和Q相与C4AF的共存条件,构造Q相-C2S-C4AF水泥系统,对此系统水泥形成条件进行研究.研究表明:Q相与C2S和Q相与C4AF能够共存,可以组成Q相-C2S-C4AF-C12A7水泥系统.在Q相-C2S-C4AF-C12A7水泥系统中,Q相在1270℃开始生成,随着温度的升高,Q相的生成量逐渐增大;采用V2O5对β-C2S具有较好的稳定作用.随着C4AF量的增加,Q相的量也在增加,同时,烧成温度降低.
关键词:
Q相
,
Q相-C2S-C4AF水泥
,
形成条件
,
抗压强度
Powder Diffraction
The crystal structure of K(2)Zn(PO(3))(4) was determined and refined using the Rietveld method based on the isostructure model of K(2)Cu(PO(3))(4). This compound belongs to the monoclinic system with space group Cc and lattice parameters of a=11.0941(2) angstrom, b=12.5215(3) angstrom, c=7.6597(2) angstrom, and, beta=102.47(2)degrees. The chemical formula unit per unit cell is Z=4 and the calculated density is 2.938(3) g/cm(3). Zigzag [PO(3)](infinity) chains formed along the a axis, and their period contains eight PO(4) tetrahedrons. (C) 2009 International Centre for Diffraction Data. [DOI: 10.1154/1.3076081]
关键词:
K(2)Zn (PO(3))(4);crystal structure;powder diffraction;Rietveld;refinement;zno;refinement
贠鹏飞
,
杨英丽
,
郭荻子
,
巨建辉
,
苏航标
,
邢健
钛工业进展
doi:10.3969/j.issn.1009-9964.2012.02.006
通过改变钛管材冷轧过程中的工艺参数,研究了不同相对减壁量与相对减径量的比值(Q值)对小口径TA2管材组织和性能的影响.结果表明:轧制Q值对管材组织性能影响较大,通过合理控制成品管材的轧制Q值可获得组织性能良好的TA2管材；对于φ6 mm×l mmTA2管材,Q值控制在1.65,变形率ε取53.3％时,可获得最佳的强塑性匹配.Q值影响冷加工过程中晶粒的破碎程度、均匀度及织构分布,因此可通过调整Q值的大小来控制管材的组织、织构,进而得到与之相匹配的良好的力学性能.
关键词:
TA2管材
,
Q值
,
显微组织
,
力学性能
