Ml(Ni4.55-xCOxMn0.4Ti0.05)合金的相结构与电化学性能

对Ｍｌ（Ｎｉ４．５５－ｘＣｏｘＭｎ０．４Ｔｉ０．０５）合金（ｘ＝０．０～０．８）的相结构、气态吸放氢特性及电化学性能进行一系统的研究。结果表明,在ｘ≤０．３的组成范围内。合金保持单一的ＬａＮｉ５相：当ｘ〉０．３时,合金中析出多种第二相,且第二相总量随Ｃｏ含量的增加而增多。随合金Ｃｏ含量的增加,晶胞体积增大,吸放氢平台下降,滞后减小,但;定氢容量降低,在Ｘ≤０．３的组成范围内,合 Ｃｏ含量增大提高了     

LaNi5—xMx合金氢化物贮氢性能的计算与预报

在研究了ＬａＮｉ５－ｘＭｘ合金氢化物（Ｍ＝Ｃｒ,Ｍｎ,Ｆｅ,Ｃｏ,Ｎｉ,Ｃｕ,Ａｌ,Ｇａ,Ｇｅ和Ｓｉ）生成焓、吸氢量与组成、键参数之间的关系的基础上,建立了生成焓与吸氢量的数学模型,给出了影响生成焓、平衡氢压及吸氢量的主要因素及其影响程度的大小。结果表明：在所研究的合金体系中,元素的电子浓度、原子尺寸越小,电负性差越大,合金的氢化生成焓越小,合金氢化物越稳定;元素电负性差、原子尺寸、电子浓度等越小     

Ml1—xCaxNi5合金的氢化物稳定性研究

系统研究了Ｍｌ１－ｘＣａｘＮｉ５系贮氢合金的氢化物稳定性（以合金的氢化物的放氢平台压力来表征）及其影响因素。提出了Ｃａ部分取代Ｍｌ后对Ｍｌ１－ｘＣａｘＮｉ５系贮氢合金的氢化物的稳定性影响的两个因素,即几何因素和电子因素,并由此导出了合金的氢化物的放氢平台压力与合金晶胞体积的关系式：ｌｎＰ＝－１．１４８５８Ｖ２＋１９５．５６２４Ｖ－８３２２．０５６２理论曲线与实验结果吻合。     

非化学计量比贮氢合金M1（Ni0.71Co0.15Al0.06Mn0.08）x的？…

研究了化学配比ｘ对贮氢合金Ｍ１（Ｎｉ０．７１Ｃｏ０．１５Ａｌ０．０６Ｍｎ０．０８）ｘ（４．６≤ｘ≤５．２）的结构、组织、电化学性能和ｐ－ｃ－Ｔ特性的影响。结果表明,随着ｘ增大非化学计量比合金点阵常数ａ值减小,ｃ值增大,单胞体积减小,当ｘ＝５．２时ｃ／ａ达到最大值。ｘ＝５．０的化学计量比合金具有最小的点阵常数和单胞体积。放电容量、充放电循环稳定性和ｐ－ｃ－Ｔ曲线平台压均随着ｘ增大而提高,当ｘ＝５．２     

Zr_（1－x）Ti_xM_（2．1）合金（M＝V_（0．1）Ni_（0．53）

Ｚｒ_（１－ｘ）Ｔｉ_ｘＭ_（２．１）合金（Ｍ＝Ｖ_（０．１）Ｎｉ_（０．５３）Ｍｎ_（０．３２）Ｆｅ_（０．０５）的吸氢特性和电化学特性用小电弧炉在氩气保护下熔炼了Ｚｒ１－ｘＴｉｘ（Ｖ０．１Ｎｉ０．５３Ｍｎ０．３２Ｆｅ０．０５）２．１（Ｘ＝０、０．１、０?..     

混合稀土贮氢合金（Ml）xNi3.8Co0.75Mn0.4Ti0.05）相结构 …

对（Ｍｌ）ｘ（Ｎｉ３．８Ｃｏ０．７５ＭｎＴｉ０．０５）合金（ｘ＝０．９０～１．１０）的相结构,热力学性能及合金电极的充放电性能进行了研究。结果表明：在ｘ〈１．００的成分范围内,合金保持单一的ＬａＮｉ５相;当ｘ≥１．００时,合金中析出多种第二相,且总量随ｘ的增加而增多。随着ｘ的增加,合金的晶胞体积及氢化物生成焓（－ΔＨ）增大,吸放氢平台压力降低,宽度增加。合金的最大放电容量在ｘ＝１．００时达到最大值     

稀王含量对MmNi5湛储氢合金性能的影响

测试了ＭｍｘＮｉ３．８Ｃｏ０．６Ｍｎ０．５５Ｔｉ０．０５（ｘ＝１．０５,１,０．９５）合金的充放电特性及循环寿命,当ｘ＝１．０５时,合金有较高的放电容量而循环寿命略有降低,这主要归因于稀土元素有较好的吸氢特性且易在晶界处偏析,形成ＭｎＮｉ相,当ｘ＝０．９５时,合金的放电容量及循环寿命显著降低,它是由于合金中的Ｍｎ向晶界处偏析,且极易溶于６ＭＫＯＨ中,破坏了合金的表面,降低了放电容量和循环寿命。     

稀土含量对MmNi_5基储氢合金性能的影响

测试了ＭｍｘＮｉ３．８Ｃｏ０．６Ｍｎ０．５５Ｔｉ０．０５（ｘ＝１．０５,１,０．９５）合金的充放电特性及循环寿命。当ｘ＝１．０５时,合金有较高的放电容量而循环寿命略有降低,这主要归因于稀土元素有较好的吸氢特性且易在晶界处偏析,形成ＭｍＮｉ相。当ｘ＝０．９５时,合金的放电容量及循环寿命显著降低,这是由于合金中的Ｍｎ向晶界处偏析,且极易溶于６ＭＫＯＨ中,破坏了合金表面,降低了放电容量和循环寿命。     

In对Pd氢化的影响

本文使用超微高压天平装置，在压力为０．００１－３．５ＭＰａ，温度为３８１－６２１Ｋ范围内测得纯Ｐｄ和４种成分Ｐｄ－Ｉｎ合金的吸放氢等温线。结果表明：价电子浓度低于０．５，晶格膨胀占主导作用，氢的溶解度随Ｉｎ含量增加而升高；价电子浓度高于０．５，费米能升高占主导作用，氢溶解度随Ｉｎ含量增加而降低。这同对Ｐｄ－Ａｇ，Ｐｄ－Ｓｎ合金中Ａｇ，Ｓｎ的作用解释相似，即它们在合金中对氢的溶解度确有上述两种相反的影响。     

Nd-Co-B非晶合金的贮氢性能

研究了ＮｄｘＣｏ８５－ｘＢ１５（ｘ＝５～３０）非晶合金的贮氢性能。所研究的合金是用纯度为９９．９９％的钴、９９．９９％的钛和钴－４６ａｔ％硼合金料,在氮气氛下电弧熔炼的合金锭,由该合金锭通过熔体旋淬（于氩气氛中）制得非晶条带（１ｍｍ宽×２０ｍ厚）。用电阻法测定非晶合金的晶化温度Ｔｘ。所研究的非晶试样不经任何预处理,在１ＭＰａ氢气和４２３Ｋ下进行吸氢处理。根据在吸氢时的压力降,或根据在吸氢后所测得的热解吸谱,来计算氢含量。用Ｘ射线衍射分析研究了非晶合金试样在氢化前后的原子结构。详细研究了Ｎｄ２０Ｃ…     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.