材料期刊网

Co-Ga二元系β相正电子湮没的研究

黄懋容 , 殷定贞 , 曹玔 , 张玉苓

金属学报

<正> 在Co-Ga二元系中,β相的理想成分CoGa在室温的单相均匀范围为36.3—59.8at.-％Ga,它属于立方晶系的CsCl型结构,其点阵常数随Ga成分而变化,在接近理想成分的48at.-％Ga处有一最大值。在富Co端,为替代式固溶体。因为Co原子半径比Ga小,所以可以用原子半径大小来解释其实验现象。但在理想成分的富Ga一端,如果也属于替代式固溶体,则随着Ga含量的增加,点阵常数应增加,但实验的结果与此相反,因此文

关键词: Co-Ga二元系 , β-phase , positron annihilation , solid solution

制备方法对W--10\%Ti合金组织性能的影响

王庆相范志康杨怡

材料研究学报

以高纯钨粉、钛粉和TA2钛片为原料, 分别采用液相烧结法和熔渗法制备了Ti含量为10\%的W--Ti合金; 测量了W--10%Ti合金的密度和杂质(C、N和O)含量, 研究了不同方法制备的W--Ti合金的相组成和微观形貌. 结果表明, 熔渗法制备的W--Ti合金致密度达94%以上, 相结构由含有较多富Ti相的固溶体β(W/Ti)组成；液相烧结的合金致密度为90%左右, 组织相对均匀；两种方法制备的合金杂质(C、N和O)含量均较低. 探讨了液相烧结制备W--10%Ti合金时固溶体扩散形成的机理.

关键词: 金属材料 , W--Ti alloy , infiltration , liquid--phase sintering , solid solution , density

合金元素及碳在Fe-Mn-Cr-C合金中的不均匀分布对γ→α′转变的影响

郑炀曾 , 张福成

金属学报

用内转换Mossbauer谱分析了Fe-Mn-Cr-C合金冷变形前后合金元素原子与碳原子的不均匀分布和相组成。发现该合金在固溶处理状态时为两类奥氏体,即无碳奥氏体和含碳奥氏体;经变形诱发出不含碳与合金元素的无碳马氏体(类α-Fe)及含碳与合金元素的合金马氏体。理论计算和试验证实:该合金中奥氏体向马氏体转变是受奥氏体晶胞内共价键中共用电子对的数目(n_A值)大小所控制。合金元素原子与碳原子之间形成结合力较强的C-M_e共价键,这对合金马氏体的形成具有强烈的阻碍作用。

关键词: 固溶体的不均匀性 , solid solution , Mossbauer spectroscopy , strain induced martensite

组织状态对Al-Zn-In-Mg-Ti合金电化学性能的影响

文九巴 , 李元侦 , 赵胜利 , 马景灵 , 卢现稳

腐蚀学报（英文）

对比了铸态的与经固溶、退火和固溶+时效处理的Al-5Zn-0.02In-1Mg-0.05Ti合金金的显微组织, 分别测量四种组织状态合金的开路电位, 工作电位, 极化曲线和电化学阻抗 (EIS), 并用等效电路R_L(CR_p(QR_d)(L₁R_a1)(L₂R_a2)) 进行了解析. 研究了不同组织状态对 Al-5Zn-0.02In-1Mg-0.05Ti合金电化学性能的影响. 结果表明: 经过退火处理的试样与铸态、固溶态和固溶+时效态试样相比, 第二相大小和数量适中、开路电位较负、工作电位稳定、电流效率最高且实际电容量最大.

关键词: 电化学性能 , current efficiency , solid solution , annealing , aging

体心立方金属中位错与间隙原子相互作用的回顾--机械波谱术研究

金属学报 doi:10.3321/j.issn:0412-1961.2003.11.006

根据有关术语、实验结果和理论处理方法的现有数据,对冷加工峰,200,220或250℃峰,Snoek-Koster(SK)峰,以及Snoek-Ke-Koster(SKK)峰进行了评估.并特别强调了葛庭燧教授(Ke)为理解冷加工峰所作的贡献.同时,对由(1)Schoeck,(2)Seeger,(3)王业宁等人,(4)Magalas 和Ngai,以及(5)Ogurtani等人发展的现有理论模型进行了简要的综述.

关键词: Snoek-Koster峰 , 冷加工峰 , Snoek弛豫 , Cottrell气团 , 葛庭燧 , 内耗 , 机械波谱学 , 位错 , 固溶体 , 铁 , 碳 , 氮

INVESTIGATION OF SURFACE MORPHOLOGY, STRUCTURE AND ELECTROCATALYTIC PROPERTIES FOR O_2 EVOLUTION OF TITANIUM BASED IrO_2+Ta_2O_5 COATINGS

J.M Hu , J.X. Wu , H.M Meng , YR. Zhu , D.B. Sun and D.J. Yang(Beijing Corrosion and Protection Center , Open Laboratory of Corrosion , Erosion and Surface Technology , University of Science and Technology Beijing , Beijing 100083 , China)

金属学报(英文版)

Titanium based IrO2 +Ta2O5 oxide anodes with different compositions and pyrolysis temperatures were prepared by termodecompoisition method. By using X-ray diffraction (XRD), the structure and texture coefficient of the coatings, TC(hkl), of IrO2 rutile crystal have been tested. It showed that, the crystallization processes of IrO2 and Ta2O5 in xIrO2 +(100-x) Ta2 O5 (x is in mol%) films affected and confined each other.In the mixed system, IrO2 rutile phase existed as a solid solution with Ta, and attained the maximum solubility when x=70mol%, i.e. for the coating of 70% IrO2 +Ta2O5.For the coatings of low iridium content or at low preparing tem pemture, (110) and (101) pwtered orientations were dominant. However, preferred growth of IrO2 weakened with increasing either iridium content or temperature. Three typical surface morphologies were observed by using scanning electron tnicroscopy(SEM). The crystallite size of the mixed oxide coatings were finest for the the film of 70%IrO2 +30%Ta2O5,and decreased with the pyrolysis tempemture. As the results of the finest crystallite segregating on sudece and the maxitnum solid solubility of Ir and Ta component in deposits, the coatings with the composition of 70%IrO2 +Ta2O5 prepared at 450℃ presented the mdrimutn electrocatalgtic activitg for O2 evolution in 0. 5M H2SO4 solution.UP to 550℃, Ti base suffered to oxidation resulting in decreasing anode conductivity,therefore, coatings performed a low activity.

关键词: titanium based coating anode , null , null , null , null , null

EFFECT OF NITROGEN ON MATRIX STRUCTURE OF GRAY CAST IRON

ZHAI Qijie HU Hanqi University of Science and Technology Beijing , China associate professor , Faculty of Foundry , University of Science and Technology Beijing , Beijing 100083 , China

金属学报(英文版)

Effect of nitrogen on matrix structure of 3 different varieties of gray cast iron,i.e., sub-eutectic Fe-C-Si,near-eutectic Fe-C-Si and Fe-C-Si-Mn,has been investigated. The eutectie colony structure of gray cast iron may be refined,the pearlite content increased and the micro-hardness of pearlite and ferrite raised with an addition of nitrogen.The influ- ence of nitrogen on the transformation temperature of the equilibrium and non-equilibrium phases,as well as,the solution of nitrogen in ferrite and cementite seem to be the major rea- sons to strengthening the matrix structure of gray cast iron.

关键词: nitrogen , null , null , null , null

EFFECT OF HETEROGENEOUS DISTRIBUTION OF C AND ALLOYING ELEMENTS ON γ/α′ TRANSFORMATION IN A Fe-Mn-Cr-C ALLOY

ZHENG Yangzeng ZHANG Fucheng Yanshan University , Qinhuangdao , China

金属学报(英文版)

The heterogeneous distribution of C and metallic alloying elements as well as the phase com- position changes before and after cold deformation of an Fe-Mn-Cr-C alloy have been stu- died by the use of Mssbauer spectroscopy.The austenites without and with C and metallic alloying elements are found in the alloy in as-solid solution state.While the martensites with- out and with C and alloying elements may be induced by cold deformation.The transforma- tion from austenite to martensite in the alloy is confirmed via theoretical computation and ex- periments to be controlled by the number of covalent electron pairs forming covalent bond in austenitic crystal cell of the alloy.The formation of strong covalent bond between C and me- tallic elements can vigorously retard the γ/α' transformation.

关键词: heterogeneity , null , null , null , null

Behaviour of Rare Earths in Solid Solution in Steel

LIN Qin , YE Wen , DU Yuansheng , YU Zongsen Department of Physical Chemistry , University of Science and Technology Beijing , 100083 , China.

材料科学技术（英文）

The contents of rare earth metals(REM) in solid solution in 16 Mn steel were determined by means of inductive coupling plasma (ICP) spectroscopy.The amount of REM in solid solution is only a few ppm in the steel with MnS inclusions, which rises slightly with the increasing of REM content in steel.At RE/S>1.9,the MnS inclu- sions in steel disappear completely,the REM con- tent in solid solution increases rapidly with the in- creasing of REM content.The solubility of cerium in 16 Mn steel(st 52)is less than 0.011 wt—% at room temperature. The results obtained indicate that REM in sol- id solution reduce the amount of pearlite and in- crease that of ferrite and its microhardness.Dis- solved REM oculd increase temperature of critical points,alleviate band structnre and suppress growth of austenite grains.

关键词: rare earth , null , null

开放体系下碳热还原氮化法制备（Cr,Ta）2 CN 固溶体粉末的研究

张豪 , 叶金文 , 刘颖 , 马世卿

功能材料 doi:10.3969/j.issn.1001-9731.2015.增刊(Ⅰ).016

以Cr2O3、Ta2O5和纳米碳黑为原料,在开放体系的流动N2气氛条件下,采用碳热还原氮化法制备出了(Cr,Ta)2CN固溶体粉末,利用XRD、SEM、EDS等分析测试手段对制备过程中的物相演变规律和微观形貌变化进行了研究.研究结果表明,碳热还原氮化法制备(Cr,Ta)2CN固溶体粉末过程中物相演变顺序为Cr2O3、Ta2O5、C→Cr2O3、Cr3C2、Cr7C3、CrTaO4、C→Cr2O3、Cr7C3、CrTaO4→(Cr,Ta)2CN.在N2流量为500mL/min、烧结温度为1500℃保温2h的条件下,可制备出粒度约5μm、游离碳和氧含量分别为0．16％,0．085％的单相(Cr,Ta)2CN固溶体粉末.

关键词: 开放体系 , 碳热还原氮化法 , (Cr,Ta)2CN , 物相演变 , 固溶体