Leaching behavior of butanedionedioxime as gold ligand

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｒｅａｒｅｔｗｏｔｙｐｅｓｏｆｏｒｂｉｔａｌｓｉｎｏｕｔｅｒｅｌｅｃｔｒｏｎｏｒｂｉｔａｌｓｏｆｇｏｌｄａｎｄｉｔｓｌｉｘｉｖｉａｎｔｓ[1,2 ] .ＯｎｅｉｓｃａｌｌｅｄＨＯＥＯ(ｈｉｇｈｅｒｏｃｃｕｐｉｅｄｅｌｅｃｔｒｏｎｉｃｏｒｂｉｔａｌｓ) ,ｓｕｃｈａｓπ ｔｙｐｅＨＯＥＯｏｆｂｏｔｈ 5ｄ2(ｘ2 -ｙ2 ) ａｎｄ 5ｄ2ｚｏｆｇｏｌｄ ,ａｎｄσ ｔｙｐｅＨＯＥＯｏｆσ22 ｐｘｏｆｃｙａｎｉｄｅ;ａｎｄａｎｏｔｈｅｒｃａｌｌｅｄＬＵＥＯ(ｌｏｗｅｒｕｎｏｃｃｕｐｉｅｄｅｌｅｃｔ…     

Phase equilibria and electrical properties of Nd2O3-SrO-TiO2 system

１ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｃｏｎｎｅｃｔｉｏｎｗｉｔｈｏｕｒｒｅｓｅａｒｃｈｏｎｔｅｒｎａｒｙｃｏｍｐｏｕｎｄｕｓｅｄｆｏｒｄｉｅｌｅｃｔｒｉｃｍａｔｅｒｉａｌ,ｔｈｅｓｙｓｔｅｍｏｆＮｄ２Ｏ３ＳｒＯＴｉＯ２ｗａｓｉｎｖｅｓｔｉｇａｔｅｄ．ＯｔｈｅｒｔｈａｎｓｏｍｅｃｏｍｐｏｕｎｄｓｒｅｐｏｒｔｅｄｂｙＳｉｄｏｒｏｖａ［１］,ｔｈｉｓｓｙｓｔｅｍｈａｓｎｏｔｂｅｅｎｒｅｐｏｒｔｅｄｓｙｓｔｅｍａｔｉｃａｌｌｙ．Ｏｕｒｓｐｅｃｉａｌｉｎｔｅｒｅｓｔｆｏｃｕｓｅｄｏｎｔｈｅｐｒｏｂｌｅ…     

Molecular dynamics of structural properties of molten CaO-SiO2 with varying composition

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｓｔｕｄｙｏｆｍｏｌｔｅｎｓｔｒｕｃｔｕｒｅｏｆＣａＯ ＳｉＯ2 ,ｗｈｉｃｈａｃｔａｓｔｈｅｂａｓｉｃｆａｃｔｏｒｉｎｆｌｕｅｎｃｉｎｇｔｈｅｐｈｙｓｉｃａｌａｎｄｃｈｅｍｉｃａｌｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｓｉｌｉｃａｔ     

Kinetic mechanism of anodic oxidation of tantalum in nitrate melts

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴａｎｔａｌｕｍｃａｎｂｅｏｘｉｄｉｚｅｄａｔｌｏｗｔｅｍｐｅｒａｔｕｒｅｉｎ ｔｏｉｎａｃｔｉｖｅＴａ2 Ｏ5 ｗｉｔｈｃｏｍｐａｃｔｔｅｘｔｕｒｅａｎｄｓｐｅｃｉｆｉｃｒｅｓｉｓｔａｎｃｅｏｆ 1 0 18Ω·ｃｍ[1],ｗｈｉｃｈｅｎｔｉｔｌｅｓｔａｎｔａｌｕｍｇｏｏｄｃｏｒｒｏｓｉｏｎｒｅｓｉｓｔａｎｃｅａｎｄｅｌｅｃｔｒｉｃｒｅｓｉｓｔａｎｃｅ ,ａｎｄａｌｓｏｍａｋｅｓｉｔｉｍｐｏｓｓｉｂｌｅｔｏｇｅｔｔｈｉｃｋＴａ2 Ｏ5 ｆｉｌｍｓａｔｌｏｗｔｅｍｐｅｒａｔｕｒｅ .Ｔｈｅｏ…     

Simulation of droplet transfer process and current waveform control of CO_2 arc welding

1　ＩＮＴＲＯＤＵＣＴＩＯＮＣＯ2 ｓｈｉｅｌｄｅｄａｒｃｗｅｌｄｉｎｇｉｓｏｎｅｏｆｔｈｅｗｅｌｄｉｎｇｔｅｃｈｎｏｌｏｇｉｅｓｗｉｔｈｈｉｇｈｅｒｅｆｆｉｃｉｅｎｃｙ ,ｌｏｗｅｒｅｎｅｒｇｙｃｏｎｓｕｍｐｔｉｏｎ ,ｌｅｓｓｈｙｄｒｏｇｅｎｃｏｎｔｅｎｔａｎｄｈｉｇｈａｎｔｉ ｏｘ ｉｄａｔｉｏｎａｂｉｌｉｔｙ .Ｔｈｅｓｈｏｒｔ ｃｉｒｃｕｉｔｔｒａｎｓｆｅｒｉｓａｍａｉｎｆｏｒｍｉｎＣＯ2 ａｒｃｗｅｌｄｉｎｇｐｒｏｃｅｓｓ ,ｂｕｔｉｔｈａｓｔｏｏｍｕｃｈｓｐａｔｔｅｒｉｎｇ ,ａｎｄｕｎｓａｔｉｓｆ…     

Study on electrochemical surface modification of coal by FTIR and Raman spectra

1　ＩＮＴＲＯＤＵＣＴＩＯＮＨｉｇｈｓｕｌｆｕｒｃｏａｌｏｃｃｕｐｉｅｓａｌａｒｇｅ ｐａｒｔｏｆｔｈｅｗｈｏｌｅｄｅｐｏｓｉｔｏｆｃｏａｌｉｎｔｈｅＳｏｕｔｈ ＷｅｓｔａｎｄｔｈｅＥａｓｔｏｆＣｈｉｎａ .Ｗｉｔｈｏｕｔｗａｓｈｉｎｇａｎｄｄｅｓｕｌｆｕｒｉｚａｔｉｎｇ ,ｔｈｅｃｏｍｍｅｒｃｉａｌｃｏａｌｉｓｏｆｌｏｗｑｕａｌｉｔｙ ,ｌｏｗｃｏｍｂｕｓｔｉｏｎｅｆ ｆｉｃｉｅｎｃｙｗｉｔｈｌａｒｇｅｃｏａｌｗａｓｔｉｎｇ ,ｇａｓａｓｈ ,ＣＯ2 ａｎｄＮＯｘ .Ａｂｏｖｅａｌｌ,ｔｈｅｃｏｍｂｕｓｔｉｏｎ…     

Influence of size of seed grains and sintering condition on varistor properties of ZnO-Bi_2O_3-TiO_2-Sb_2O_3 ceramics

1　ＩＮＴＲＯＤＵＣＴＩＯＮＳｉｎｃｅＺｎＯｖａｒｉｓｔｏｒｃｅｒａｍｉｃｓｗｅｒｅｆｉｒｓｔｌｙｄｅｖｅｌ ｏｐｅｄｉｎ 196 8,ｓｉｇｎｉｆｉｃａｎｔｐｒｏｇｒｅｓｓｅｓｈａｖｅｂｅｅｎｍａｄｅｉｎｉｎｖｅｓｔｉｇａｔｉｏｎａｎｄａｐｐｌｉｃａｔｉｏｎｏｆｔｈｅｍａｔｅｒｉａｌ.Ａｓａｋｉｎｄｏｆａｄｖａｎｃｅｄｆｕｎｃｔｉｏｎａｌｃｅｒａｍｉｃｓ,ＺｎＯｖａｒｉｓｔｏｒｃｅｒａｍｉｃｓｈａｖｅｂｅｅｎｗｉｄｅｌｙｕｓｅｄｉｎｅｌｅｃｔｒｏｎｉｃｃｉｒｃｕｉｔｓａｎｄｅｌｅｃｔｒｉｃａｌｐｏｗｅｒ…     

Recent development in researches of electrochemistry of sulphide flotation at Central South University of Technology

1　ＣＯＬＬＥＣＴＯＲＬＥＳＳＦＬＯＴＡＴＩＯＮ1.1　ＮａｔｕｒａｌｆｌｏａｔａｂｉｌｉｔｙＴｈｅｉｎｈｅｒｅｎｔｈｙｄｒｏｐｈｏｂｉｃｉｔｙｏｎｃｅｔｈｏｕｇｈｔｔｏｂｅｔｙｐｉｃａｌｏｆｓｕｌｆｉｄｅｓ[1] ｉｓｎｏｗｔｈｏｕｇｈｔｔｏｂｅｒｅｓｔｒｉｃｔｅｄｔｏｓｕｌｆｉｄｅｓｓｕｃｈａｓｍｏｌｙｂｄｅｎｉｔｅａｎｄｏｔｈｅｒｍｉｎｅｒａｌｓｏｒｃｏｍｐｏｕｎｄｗｉｔｈｓｐｅｃｉａｌｓｔｒｕｃｔｕｒａｌｆｅａｔｕｒｅｓ .Ｍｉｎｅｒａｌｓｓｕｃｈａｓｍｏｌｙｂｄｅｎｉｔｅ ,ｏｒｐｉｍｅｎｔ ,ｒｅ…     

Formation mechanism of laser-clad gradient thermal barrier coatings

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＺｒＯ2 ｃｅｒａｍｉｃｓｗａｓｓｅｌｅｃｔｅｄａｓｔｈｅｍａｔｅｒｉａｌｏｆｔｈｅｒｍａｌｂａｒｒｉｅｒｃｏａｔｉｎｇｓ (ＴＢＣｓ)ｆｏｒｉｔｓｈｉｇｈｍｅｌｔ ｉｎｇ ｐｏｉｎｔａｎｄｈｉｇｈｅｘｐａｎｓｉｏｎｃｏｅｆｆｉｃｉｅｎｔ[1].ＴｈｅｍｅｔｈｏｄｔｏｐｒｏｄｕｃｅＴＢＣｓｗａｓｕｓｕａｌｌｙｐｌａｓｍａｓｐｒａｙｉｎｇｔｅｃｈｎｉｑｕｅ.Ｔｈｅｐｏｒｏｓｉｔｙｉｎｔｈｅｃｏａｔｉｎｇａｎｄｔｈｅｐｏｏｒａｄｈｅｒｅｎｃｅｂｅｔｗｅｅｎｃｏａｔｉｎｇａｎｄｓ…     

ASTUDY OF VALENCE OF YTTRIUM IN Y_2O_3 Mo CATHODE

１．ＩｎｔｒｏｄｕｃｔｉｏｎＡｓａｎｅｗｋｉｎｄｏｆｒａｒｅｅａｒｔｈｍｏｌｙｂｄｅｎｕｍｃａｔｈｏｄｅｍａｔｅｒｉａｌ,ＭｏＹ２Ｏ３ｉｓｅｘｐｅｃｔｅｄｔｏｓｕｂｓｔｉｔｕｔｅｒａｄｉｏａｃｔｉｖｅＷＴｈＯ２ｃａｔｈｏｄｅｍａｔｅｒｉａｌｓｉｎｔｈｅｆｕｔｕｒｅ．Ｍｏ４ｗｔ％Ｙ２Ｏ３ａｌｌｏｗｓ,ｒｅｌａｔｉｖｅｔｏＭｏＬａ２Ｏ３〔１２〕（ｗｈｉｃｈｈａｓｂｅｅｎｗｉｄｅｌｙｓｔｕｄｉｅｄｓｉｎｃｅ１９７０ｓｉｎｏｒｄｅｒｔｏｓｕｂｓｔｉｔｕｔｅＷＴｈＯ２ｃａｔｈｏｄｅｍａｔｅｒ…     

Mechanical properties and microstructure of Fe-Al/Al_2O_3 composite with Cr,Mo and Ti

1　INTRODUCTIONTheFe Alintermetalliccompoundhasaseriesofmerits[1,2 ] ,suchashighstrength ,lowdensity ,goodwearablityandlowcosts ,andithasbeenusedinsomefields .Butitshightemperaturestrengthislow er.Al2 O3ceramicsisoneofthestructuralmaterialswithwideapplication ,butboththehigherbrittlenessandlowertoughnesslimiteditsapplicationfields .Inordertogetonematerialwithbothhighstrengthandhightoughness,onenovelFe Al/Al2 O3compositewasfabricatedbytheauthors[3] .Ithasverywideap plicationprospectfori…     

合金化对MoSi_2室温韧性的影响

配制和电弧熔炼了MoSi2、(Mo,2at%Nb)Si2、(Mo,6at%Nb)Si2、Mo(Si,2at%Al)2、Mo(Si,4at%Al)2和(Mo,2at%Cr)Si2六种合金,用XRD、SEM-EDS、EPMA、维氏硬度计及压痕法研究了Nb、Al、Cr合金化对MoSi2组织结构、室温硬度及断裂韧性的影响.结果表明,2at%Al、4at%Al和2at%Cr三种合金均得到了单一四方C11b相;6at%Nb合金因Nb含量高,导致部分四方C11b相转变为六方C40相,合金出现灰色C11b基体相与亮白色层片状C40第二相双相组织,部分C40相中存在几乎平行排列的宽度贯穿裂纹.Nb、Al、Cr合金化都降低了MoSi2的维氏硬度,提高断裂韧性,其中2at%Nb、4at%Al合金的断裂韧性最高,达到了5.90 MPa·m1/2,提高了69%.     

Microstructure,hardness and indentation toughness of C40 Mo(Si,Al)2/ZrO2 composites prepared by SPS of MA powders

The nano- and micron-scale composite structures, Mo/Mo₅Si₃, Al₂O₃ and Mo_0.34Zr_0.20Si_0.46 phases have been observed in spark plasma sintered (SPS) C40 Mo(Si,Al)₂/ZrO₂ materials. The hardness of C40 Mo(Si,Al)₂/ZrO₂ composites is around 14 GPa. The indentation toughness lies in 2.69–2.94 MPa m^1/2 range that is approximately 50% higher than toughness of C40 Mo(Si,Al)₂ phase.     

Tool steels for cold working dies

The effect of the main alloying elements (Cr, W, Mo, Ni, Mn, Si) and carbon on the properties of die steels used for cold deformation of metals is considered. Steels heat-treated for primary and secondary hardness are studied. The problems of ensuring maximum values of the impact toughness, strength characteristics, and fatigue limit at optimum content of alloying elements are discussed. __________ Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 6, pp. 3–9, June, 2006.     

Mo(Si_(1-x)Al_x)_2/Al_2O_3复合材料的制备与强韧化

以Mo、Al、Si和Mo O_34种粉末为原料,通过燃烧合成和真空热压烧结工艺原位制备了(Si_(1-x)Al_x)_2/Al_2O_3复合材料,分析了其燃烧模式、产物相结构、微观组织和力学性能。结果表明:添加Al之后坯体的燃烧合成反应更加剧烈,燃烧模式由螺旋模式转入混沌模式。随着合金化Al含量的增加,基体相结构由C11_b型Mo Si_2转变为C40型Mo(Si,Al)_2,并且在所有复合材料中都可以鉴别出Al_2O_3衍射峰,表明通过燃烧合成技术原位制备了Mo(Si_(1-x)Al_x)_2/Al_2O_3复合材料。复合材料的断裂韧性和抗弯强度最高分别达到4.25 MPa·m~(1/2)和346 MPa,比纯Mo Si_2提高了39%和60%。复合材料的强韧化机制主要有Al合金化强韧化、Al_2O_3第二相颗粒弥散强韧化、玻璃相的消除以及断裂方式的转变。     

Mo effect on the phase stability and room-temperature fracture toughness of Nb/Nb_5Si_3 in-situ composites

Nb/Nb5Si3 in-situ composites are very attractive structural materials because these materials perform a good balance in mechanical properties, including high strength at high temperature (>1000℃) and reasonably high fracture toughness at room temperature. Metastable phase Nb3Si plays an important role in the properties of     

Correlation between microstructure and properties of fine grained Mo–Mo3Si–Mo5SiB2 alloys

Three phase α-Mo–Mo₃Si–Mo₅SiB₂ alloys of various compositions, namely Mo–6Si–5B, Mo–9Si–8B, Mo–10Si–10B and Mo–13Si–12B (at.%) were processed by a powder metallurgical (PM) route. Increasing the Si and B concentration in these Mo–Si–B alloys resulted in increasing volume fractions of the intermetallic phases Mo₃Si (A15) and Mo₅SiB₂ (T2) and the distribution of the three phases present in these alloys was dependent on the volume fractions of the individual phases. Above volume fractions of about fifty percent, bcc Mo solid solution (α-Mo) formed the matrix. Consequently, Mo–6Si–5B and Mo–9Si–8B alloys, which possessed a continuous α-Mo matrix provided increased fracture toughness at ambient temperatures. Additionally, a decreased BDTT of about 950 °C is caused by the homogeneous α-Mo matrix. In contrast, Mo–13Si–12B with 65 vol.% of the intermetallic phases that formed the matrix phase in this material had a BDTT value higher than 1100 °C, while the strength at elevated temperatures up to 1300 °C was significantly increased compared to alloys that have the α-Mo matrix. Alloy compositions with ≥50 vol.% of intermetallic phases (corresponding to alloys containing a minimum of 9 at.% Si and 8 at.% B) were oxidation resistant with minimal mass loss under cyclic conditions for 150 h at 1100 °C due to the formation of a dense borosilicate glass layer that protects the material surface.     

Partition behavior of alloying elements and phase transformation temperatures in Co–Al–W-base quaternary systems

The phase equilibria among γ (A1), γ′ (L1₂), χ (D0₁₉), β (B2) and μ (D8₅) phases and the γ′ solvus and γ solidus temperatures were investigated in the Co–Al–W-based quaternary systems with alloying elements of Ti, V, Nb, Ta, Cr, Mo, Mn, Fe, Ni, Si, Zr, Hf, Ru and Ir by electron probe microanalysis (EPMA) using multiphase alloys and by differential scanning calorimetry (DSC). It was found that Ta, Nb, Ti, V, Mo and W are partitioned to the γ′ or χ phase rather than to the γ phase, while Cr, Mn and Fe tend to be distributed to the γ phase. The correlation between the partition coefficient of alloying elements between γ/γ′, γ/χ and γ/β phases and ab initio formation energy of Co₃X (L1₂), Co₃X (D0₁₉) and CoX (B2) was respectively obtained. It was also found that the γ′ solvus temperature increases by the addition of the γ′ former elements such as Ta, Nb and Ti, which decreases the γ solidus temperature.     

多相Nb硅化物的断裂韧度和高温力学性能

通过机械合金化和热压烧结制备了4种近理论密度的Nb-xSi-2Fe（x=3,6,10,16）原位复合材料。X射线衍射（XRD）分析表明：制备的复合材料均由铌固溶体（Nbss）相、Nb3S i相、Nb5S i3相和Nb4Fe3Si5相组成。各物相的平均晶粒尺寸为3μm,并且呈等轴状。Nb-Si-Fe复合材料随着S i含量的增加断裂韧度减小,Nb-Si-Fe室温断裂韧度大于11MPam1/2,Nbss相的塑性变形能够减小界面的应力集中延迟裂纹的形核从而改善这些复合材料的断裂韧度。Nb-Si-Fe复合材料在1 300℃时的抗拉强度随S i含量的增加而增加。复合材料在1 300℃时的抗拉强度为112~237 MPa,拉伸延伸率为54%~95%,室温断裂韧度大于11 MPam1/2。     

Si含量对CrSiN涂层结构和性能的影响

目的在室温条件下,采用物理气相沉积(PVD)磁控溅射沉积方法,通过控制Si靶功率制备具有不同Si含量的CrSiN涂层,以探究Si元素对涂层结构和性能的影响。方法通过X射线衍射、能谱仪测试、纳米压痕测试、维氏硬度压痕测试和摩擦磨损实验,分别评价CrSiN涂层的结构、硬度、韧性和耐磨性能,并通过扫描电子显微镜对压痕形貌进行分析。结果所有CrSiN涂层均呈(111),(200)取向的Na Cl结构。随着Si含量增加,XRD峰呈宽化趋势,晶粒细化效果明显。随Si元素的加入,CrSiN涂层硬度、模量和韧性均呈先增加后降低的趋势。相比Cr N涂层,Si的原子数分数为3.2%时,CrSiN涂层的硬度由21.4 GPa增至35.7 GPa,模量由337.7 GPa增至383.9 GPa,塑性指数由0.5增至0.55,实现了强韧一体化。加入Si元素,CrSiN涂层的耐磨损性能得到改善,且Si的原子数分数为3.2%,磨损率最低,为1.0×10~(-17)m~3/(N·m),提高了约一个数量级。结论 Si元素的加入可以有效改善CrSiN涂层的结构,提高CrSiN涂层的硬度、韧性和磨损性能,但需加入适量的Si,才可实现性能最优化。