V+TiFe_(0.85)Mn_(0.15)复相合金的储氢特性

研究了(100-x)%V+x%TiFe0.85Mn0.15(x=50,60,70)(质量分数,下同)合金的储氢特性。讨论了添加TiFe0.85Mn0.15对钒基合金活化、吸放氢性能与组织结构的影响。研究表明,所有试验合金无需活化处理即可吸氢。在室温和4.0MPa下,40%V+60%TiFe0.85Mn0.15合金的有效氢容量达到207ml/g。

Mg＋10％TiFe1-xCrx(x=0，0．3)复相合金的储氢特性

采用高能机械球磨法制备了Mg＋10％TiFe1-xCk（x=0，0．3）复相储氢合金，对比研究了球磨复相合金和球磨纯镁的微结构与储氢性能．研究结果表明：在纯Mg中添加质量分数为10％的TiFe1-xCk（x=0，0．3）进行复合球磨，可以明显提高其吸放氢性能；在相同温度条件下，x=0．3的含铬复相舍金具有最佳的吸放氢性能，其中在613K下的吸氢容量（氢的质量分数）为7．14％，放氢容量（氢的质量分数）为6．91％；在493～573K的较低温度下，含铬复相合金表现出更好的放氢动力学性能．通过XRD、SEM、EDS分析研究表明，TiFe1-xCrx（x=0，0．3）合金粉以细小颗粒的形式分散镶嵌在镁粉基体上成为催化活性点，改善了体系的吸放氢性能．

快淬速度及合金元素添加对Nd_(2)Fe_(14)B/α-Fe纳米复相合金微观组织的影响

通过真空电弧熔炼炉制备了Nd_(2)Fe_(14)B/α-Fe合金铸锭,对其铸态组织进行观察。观察发现,由于坩埚底部配有冷却系统,铸锭底部晶粒尺寸(15μm)小于顶部晶粒尺寸(50μm)。随后采用熔体快淬法将合金铸锭制备成Nd_(2)Fe_(14)B/α-Fe纳米复相合金薄带,研究了不同快淬速度对薄带微观组织的影响。结果表明,随着快淬速度的增加,薄带晶粒尺寸逐渐减小,当快淬速度为30 m/s时,晶粒尺寸达到最小255 nm。添加Ti、Nb元素后采用熔体快淬法制备了Nd_(2)(FeTiNb)_(14)B/α-Fe纳米复相合金薄带。结果是,当快淬速度为30 m/s时,薄带晶粒尺寸减小至约100 nm。

复相Al_3Ti基合金的高温强化

报导了对 Al3Ti结合合金进行复相强化的研究 ,利用适量的 Nb合金化 ,在 L12 Al3Ti基体中形成分散的第二相 ,其室温和高温强度显著提高 ,韧性也有改善。改变制备工艺 ,使合金发生重有序和析出过程 ,形成具有高度弥散微粒的复相细晶组织 ,合金的室温和高温强度进一步提高。

高能球磨对复相Al_3Ti基金属间合金组织和性能的影响

将铸态Al67Mn8Ti24Nb1合金经不同时间高能球磨后所得的村末烧结、热压成形，其各自组织均恢复至Ll2＋DO22复相结构，晶粒明显细化，DO22第二相更为细小弥散；球磨10h粉末的成形合金经压缩试验。σ0.2和σf分别为936和1846Mpa，εf为16．8％，均明显高于该合金涛态时的性能；进一步延长球磨时间真粉末成形合金的强度和塑性呈下降趋势、球磨60h粉末成形合金甚至不能发生塑性变形；高温退火处理使各状态合金压缩性能均有不同程度的改善。

纳米复合永磁合金Nd_9Fe_(85-x)Ti_4C_2B_x(x=10～15)的热物性和相变的研究

采用差热分析（DTA）和X 射线衍射分析（XRD）相结合的方法对纳米复合永磁合金Nd9Fe85-xTi4C2Bx （x=10~15）铸锭进行研究,确定了合金的液相线温度、固相线温度以及其它相变的温度区间,推断了合金凝固过程中发生的相变.结果表明,随着合金铸锭中B含量从10%（原子分数）增加至15%（原子分数）,合金的液相线温度从1498.5 K 逐步降低至1472.5K,而固相线温度从1353.5 K 逐步升高至1358.3K.可以推断合金铸锭的凝固相变如下：在它们的液相线下的第-个相变温度区间,L→γGFe,L＋γGFe→Nd2Fe14B;在第二个相变温度区间,L→γGFe,L→Nd2Fe14B＋Fe3B;在第三个相变温度区间,L→Nd2GFe14B,L→Nd2Fe14B＋Fe3B ＋ Nd1.1Fe4B4.

复相La-Mg-Ni系贮氢合金制备技术新进展

综述了近年来不同制备技术影响复相La-Mg-Ni系贮氢合金微观结构与电化学性能的研究现状,从合金的微观结构对其电化学参数起着决定性作用这一基点出发,比较了不同制备技术的优缺点,为选择具有优异电极性能贮氢合金的制备技术参数提供思路和依据。

新型低合金铸态复相耐磨钢的组织与性能

开发了一种新型多元合金化铸态复相耐磨钢 ,化学成分 (% ) :0 3 0～ 0 45C ,1 5～ 3 0Mn ,0 8～1 5Cr ,0 8～ 1 2Si,0 2～ 0 8Mo ,0 10～ 0 2 5V ,0 0 5～ 0 10Ti,0 0 0 5～ 0 0 12B ,该新型耐磨钢为马氏体、下贝氏体加薄膜状残余奥氏体的复相组织 。

模糊分析方法在复相材料组织及性能设计上的应用

利用模糊分析的方法，确定了复相材料组织参量对性能的隶属函数．并运用模糊线性加权变换对４种不同组织参量的铁素体（Ｆ）－马氏体（Ｍ）双相钢的强度。

金属材料表面改性及强化技术研究进展

本文主要从金属表面合金化、金属光整加工技术、表面涂层制备工艺三方面介绍了当前金属材料表面改性和强化技术的应用和发展态势,指出表面改性及强化技术是充分发挥金属材料潜力、拓展其应用领域的一条行之有效的途径。

微放电法改善工具表面性能

本文介绍用微放电法（电磁法），使金属工具或零部件表面的性能得到大幅度的改善，例如在塑性金属基本表面赋予高耐磨性，高耐热性，高硬度，高耐蚀性等指定性能的合金化薄层，包括在表层中含有硬质合金，陶瓷微粒，磨料微粒，细的金刚石，CBN等微粒。

Tribological properties of nanostructured Al_2O_3-40%TiO_2 multiphase ceramic particles reinforced Ni-based alloy composite coatings

The Ni-based alloy composite coatings reinforced by nanostructured Al2O3-40%TiO2 multiphase ceramic particles were prepared on the surface of 7005 aluminum alloy by plasma spray technology. The microstructure and tribological properties of the composite coatings were researched. The results show that the composite coatings mainly consist of γ-Ni, α-Al2O3, γ-Al2O3 and rutile-TiO2 etc, and exhibit lower friction coefficients and wear losses than the Ni-based alloy coatings at different loads and speeds. The composite coating bears low contact stress at 3 N and its wear mechanism is micro-cutting wear. As loads increase to 6-12 N, the contact stress is higher than the elastic limit stress of worn surface, and the wear mechanisms change into multi-plastic deformation wear, micro-brittle fracture wear and abrasive wear. With the increase of speeds, the contact temperature of worn surface increases. The composite coating experiences multi-plastic deformation wear, fatigue wear and adhesive wear.

Phase evolution in AlSi20/8009 aluminum alloy during high temperature heating near melting point and cooling processes

The AlSi20/8009 aluminum alloy was heated to high temperatures near the melting point and cooled to investigate the effect of external Si addition on the phase evolution of Al12(Fe,V)3 Si dispersion. Differential scanning calorimeter, scanning electron microscope, energy dispersive spectrometer and X-ray diffractometer were employed.The results showed that Al12(Fe,V)3 Si and Si phases evolved into a needle-like Al4.5 Fe Si phase and a nano-sized V-rich phase during holding the alloy at 580-600℃. With increasing holding temperature to 620-640℃, Al4.5 Fe Si and nano-sized V-rich phases evolved reversibly into Al12(Fe,V)3 Si and Si phases, of which Al12(Fe,V)3 Si occupied a coarse and hexagonal morphology. During the alloy(after holding at 640 ℃) furnace cooling to 570 ℃ or lower, Si and Al12(Fe,V)3 Si phases evolved into strip-like Al4.5 Fe Si and the V-rich phases, which is a novel formation route for Al4.5 Fe Si phase different from Al-Fe-Si ternary system.

Compatibility research of laser additive repairing TA15 forgings with Ti6Al4V-xTA15 alloy

The application of mixed powders with different mass fraction on laser additive repairing(LAR)can be an effective way to guarantee the performance and functionality of repaired part in time.A convenient and feasible approach is presented to repair TA15 forgings by employing Ti6Al4V-xTA15 mixed powders in this paper.The performance compatibility of Ti6Al4V-xTA15 powders from the aspects of microhardness,tensile property,heat capacity,thermal expansion coefficient and corrosion resistance with the TA15 forgings was fully investigated.The primaryαlaths were refined and the volume fraction of the secondaryαphase was increased by increasing the mass fraction of TA15 in the mixed Ti6Al4V-xTA15 powders,leading to varied performances.In conclusion,the mixed Ti6Al4V-70%TA15(x=70%)powders is the most suitable candidate and is recommended as the raw material for LAR of TA15 forgings based on overall consideration of the compatibility calculations of the laser repaired zone with the wrought substrate zone.

N-doped carbon-coated Fe_(3)N composite as heterogeneous electro-Fenton catalyst for efficient degradation of organics

Herein,the application of a N-doped graphitic-carbon-coated iron nitride composite dispersed in a N-doped carbon framework(Fe_(3)N@NG/NC)is investigated as a heterogeneous electro-Fenton(HE-EF)catalyst for the efficient removal of organics.The simultaneous carbonization and ammonia etching of iron-based metal organic framework(Fe-MOF)materials yielded well-dispersed N-doped carbon-coated Fe_(3)N nanoparticles with a diameter of~70 nm.The Fe_(3)N and pyridinic N endowed the composite with high HE-EF activity for decomposing the electrogenerated H_(2)O_(2) to•OH.The Fe_(3)N@NG/NC exhibited outstanding HE-EF performance in removing various organic pollutants with low iron leaching.A removal rate of 97-100%could be obtained for rhodamine B(RhB),dimethyl phthalate,methylene blue,and orange Ⅱ in 120 min at a pH of 5.0.When the solution pH was set to 3.0,5.0,7.0,and 9.0,the removal rate of RhB reached 100%,96%,92%,and 81%,respectively,in 60 min at an optimum voltage of 0.0 V(vs.reversible hydrogen electrode(RHE)).Moreover,the concentration of leached iron was expected to be below 0.03 mg/L in a wide pH range of 3.0-9.0.In addition,the RhB removal efficiency remained as high as 90%after six cycles in the reusability experiments.This work highlights the MOF-derived Fe_(3)N composite as an efficient HE-EF catalyst and the corresponding catalytic mechanism,which facilitates its application in wastewater treatment.

Effect of Mg-based spherical quasicrystal on microstructures and mechanical properties of ZA54 alloy

To improve the strength, toughness and heat-resistance of magnesium alloy, the microstrucmre and mechanical properties of ZA54 alloy reinforced by icosahedral quasicrystal phase （/-phase） particles were studied. Except α-Mg, φ-phase and τ-phase, MgZnYMn I-phase particles can be obtained in ZA54-based composites by the addition of icosahedral quasicrystal-contained Mg-Zn-Y-Mn master alloy. The introduction of MgZnYMn I-phase into ZA54 alloy has great contribution to the refinement of matrix microstructures and the improvement of mechanical properties. When the addition of Mg-based spherical quasicrystal master alloy is up to 3.5% （mass fraction）, the macro-hardness of ZA54-based composites is increased to HB 68. The impact toughness of composites reaches the peak value of 18.3 J/cm^2, which is about 29% higher than that of ZA54 mother alloy. The highest tensile properties at ambient and elevated temperatures with master alloy addition of 2.5% （473 K） are also obtained in ZA54-based composites with 3.5% （mass fraction） Mg-Zn-Y-Mn master alloy addition. The ultimate tensile strength of composites at ambient and elevated temperatures are 192.5 MPa and 174 MPa, which are 23.4% and 33.8% higher than that of ZA54 mother alloy, respectively. The improved mechanical properties are mainly attributed to the pinning effect of I-phase on grain boundaries.

Effect of Fe content on microstructure and mechanical properties of Cu-Fe-based composite coatings by laser induction hybrid rapid cladding

To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser induction hybrid rapid claddingwas investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardnessmeasurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content,the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fecontent, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-richparticles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of thecomposite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is muchtwice higher than that of the substrate.

利用落管研究微重力环境对中低熔点合金凝固过程的影响

利用50m落管对Al-Ni、Al-Cu、Ag-Cu、Al-Pb和Cu-Co等几种合金在真空下自由落体前后的硅油快淬凝固组织进行了对比研究,分析和讨论了微重力对中低熔点共晶、偏晶和包晶合金凝固过程的影响.研究结果表明,微重力对共晶合金共晶胞的生长形貌、晶胞内共晶相的生长形貌及共晶层片间距的影响因合金体系不同而不同;微重力使Al-Pb过偏晶合金中Pb粒子的尺寸和分布发生重大变化;微重力还使Cu-Co包晶合金中初生α-Co相的生长形貌发生改变.此外,研究还发现Al-Al3Ni共晶在落管中凝固时呈现出罕见的规则颗粒状共晶形貌.这些结果对于人们进一步认识和分析微重力条件下复相合金的凝固行为具有参考价值.

Synthesis of growth-type polycrystalline diamond compact (PDC) using the solvent Fe_(55)Ni_(29)Co_(16) alloy under HPHT

A growth-type polycrystalline diamond compact （PDC） was synthesized under high temperature and high pressure （HPHT）. The infiltration technique was used with an Fe55Ni29Co16 （KOV） alloy as the sintering solvent. The morphology and weight ra- tio of the PDC were investigated through scanning electron microscopy （SEM） and electron dispersion spectroscopy （EDS）. Note that the KOV alloy evenly infiltrated throughout the polycrystalline diamond （PCD） layer and WC-Co substrate in a short sintering time due to its low viscosity and high soakage capability. A transition layer confirmed the presence of the M^C phase near the interface of the PDC, which can make the diamond layer and WC-Co substrate combine as a complex material. X-ray diffraction （XRD） performed on the PCD layer confirmed the presence of cubic diamond, WC, cubic CoCx, the high tempera- ture cubic phase of c^-Co, the alloy phase of FeNix, and no graphite phase. Besides, a surface residual stress of the PCD layer, measured with reasonable accuracy using micro-Raman spectroscopy, is found to be a homogeneous compressive stress with an average value of 0.16 GPa, much lower than that of the powders-mixing method.

Thermal Analysis of Metal Foam Matrix Composite Phase Change Material

In this paper,CPCM(Composite Phase Change Material)was manufactured with metal foam matrix used as filling material.The temperature curves were obtained by experiment.The performance of heat transfer was analyzed.The experimental results show that metal foam matrix can improve temperature uniformity in phase change thermal storage material and enhance heat conduction ability.The thermal performance of CPCM is significantly improved.The efficiency of temperature control can be obviously improved by adding metal foam in phase change material.CPCM is in solid-liquid two-phase region when temperature is close to phase change point of paraffin.An approximate plateau appears.The plateau can be considered as the temperature control zone of CPCM.Heat can be transferred fiom hot source and be uniformly spread in thermal storage material by using metal foam matrix since thermal storage material has the advantage of strong heat storage capacity and disadvantage of poor heat conduction ability.Natural convection promotes the melting of solid-liquid phase change material.Good thermal conductivity of foam metal accelerates heat conduction of solid-liquid phase change material.The interior temperature difference decreases and the whole temperature becomes more uniform.For the same porosity with a metal foam,melting time of solid-liquid phase change material decreases.Heat conduction is enhanced and natural convection is suppressed when pore size of metal foam is smaller.The thermal storage time decreases and heat absorption rate increases when the pore size of metal foam reduces.The research results can be used to guide fabricating the CPCM.