Ta—12W合金的高温拉伸特性

测量了再结晶态Ｔａ－１２Ｗ合金板的室温至１６００℃的拉伸性能。在室温下拉伸,Ｔａ－１２Ｗ合金展示出良好的固溶强化和优良的延性。提高试验温度,合金的强度和延性均逐渐下降。     

WC—Co硬质合金中TaC,Cr3C2添加剂的作用机理

研究了添加剂ＴａＣ、Ｃｒ３Ｃ２对ＷＣ－１０Ｃｏ合金组合结构和性能的影响及相关机理。结果表明，添加少量ＴａＣ（ｗ＝２％）、Ｃｒ３Ｃ２（ｗ＝０．４４％）可导致ＷＣ－１０Ｃｏ合金的ＷＣ晶粒明显细化、ＷＣ邻接度下降、γ相平均自由程减小，但强韧性有所下降；Ｃｒ３Ｃ２助长ＷＣ－１０Ｃｏ合金ＷＣ晶粒断续长大；ＴａＣ－ＷＣ固溶体耐碱蚀性差；合金断口中沿ＷＣ－ＷＣ晶界脆断比例增加，ＴａＣ－ＷＣ固溶体晶粒倾向于穿晶劈     

应用d－电子合金设计理论发展新型抗热腐蚀单晶镍基高温合金──Ⅲ．性能评价

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程．该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０－９０℃，其持久强度达到ＣＭＳＸ－２的水平，试验证明ｄ－电子合金设计理论可以用于研制开发高性能抗热腐蚀单晶镍基高温合金．     

APPLICATIONS OF d-ELECTRONS ALLOY DESIGN THEORY TO DEVELOPMENT OF HOT CORROSION RESISTANT Ni－BASE SINGLE CRYSTAL SUPERALLOYS Ⅲ. Characterization of Properties

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａ１－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程．该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０－９０℃，其持久强度达到ＣＭＳＸ－２的水平，试验证明ｄ－电子合金设计理论可以用于研制开发高性能抗热腐蚀单晶镍基高温合金．     

WC－Co硬质合金的矫顽磁力

研究了γ相分布和淬火处理对ＷＣ－Ｃ０合金矫顽磁力Ｈｃ的影响规律和机理。结果表明：ＷＣ－Ｃ０合金Ｈｃ与γ相分布有着密切关系，其随合金中Ｃｏ％和ｄｗｃ增加而降低的程度在低Ｃｏ合金范围内符合线性规律，在高Ｃｏ合金中则平缓降低，这是由于ＷＣ邻接度Ｃｗｃ－ｗｃ对γ相磁畴在反磁化过程中的阻滞作用的影响；淬火处理提高ＷＣ－Ｃｏ合金的Ｈｃ主要是由于淬火对γ相成分和应力状态的影响。     

Ta—10W衬管与钢管段的爆炸复合

研究了Ｔａ－１０Ｗ全金衬管与ＣｒＮｉＭｏ钢管段的爆炸复合，观察了爆炸复合界面，讨论了装药量与管段变形量的关系。分析了爆炸复合对管段力学性能的影响，结果表明，取相同条件下平板复合炸药厚度的６０％左右作为圆内复工艺参数的方法是可行的，在装药质量比Ｒ＝０．８条件下，已将０．４ｍｍ厚Ｔａ－１０Ｗ合金衬管可靠地内复在ＣｒＮｉＭｏ钢管段内，结合界面是波状结合。     

应用d—电子合金设计理论发展新型抗热腐蚀单晶镍基高温合金 Ⅲ.性…

根据ｄ－电子合金理论研究了合金系统Ｎｉ－１６Ｃｒ－９Ａｌ－２Ｗ－１Ｍｏ－４Ｃｏ－Ｔｉ－Ｔａ－Ｎｂ（ａｔ．－％）的热腐蚀行为。选择了最佳成分范围内的４种成分进行单晶生长及性能评价。确定了性能匹配最佳的合金成分（ａｔ．－％）为：Ｎｉ－１６Ｃｒ－９Ａｌ－２Ｗ－１Ｍｏ－４Ｃｏ－３．１２５Ｔｉ－０．８７５Ｔａ。完成了整个合金设计过程。该合金抗热腐蚀能力达到或超过ＩＮ７３８ＬＣ，使用温度比ＩＮ７３８ＬＣ高７０     

Ti—6.5Al—2Zr—1Mo—1V钛合金简介

平板撞击载荷造成靶样品层裂过程包括孔洞成核，微裂纹生长成宏观裂纹，裂纹切变扩展导致靶局部或完全剥离。本文重点介绍了Ｔａ和Ｔａ－Ｗ合金靶在中低入射应力的平板撞击载荷下裂纹萌生和发展情况，采用金相和扫描电镱观察和分析了Ｔａ和Ｔａ－Ｗ合金靶的原始显微组织和气炮加载试验后回收靶的显微组织变化．研究了靶样品在平板冲击载荷下裂纹萌生和发展同原始晶粒尺寸及靶中Ｗ含量的关系。结果表明，随着合金元素Ｗ的添加及Ｗ含量     

铁基合金化学镀层的显微硬度

通过显微硬度测量和Ｘ射线衍射结构分析，研究了化学镀Ｆｅ－Ｍｏ－Ｂ非晶态合金、Ｆｅ－Ｗ－Ｂ晶态合金镀层的显微硬度随成分、热处理及结构的变化关系。结果表明：两合金系的显微硬度均随类金属Ｂ含量增加而提高，电子浓度的变化规律则相反。且热处理过程中，随退火温度增加，Ｆｅ－Ｗ－Ｂ合金镀层的显微硬度出现峰值，这与晶化析出相的类型及数量有关。     

铬含量及时效对快速凝固Cu－Cr－0．05Zr合金组织与性能的影响

研究了铬含量及时效对快速凝固Ｃｕ－Ｃｒ－０．０５ｚｒ合金组织与性能的影响。结果表明，该合金系的硬度随过饱和的铬含量增加而线性提高；临界凝固速度随铬含量的增加而增大；铬的析出会降低它在铜中的极限溶解度；当凝固速度高至使柱状晶间距小于１μｍ时，铬在单相过饱和固溶体中的极限溶解度可超过３％。合金Ｃｕ－０．８４Ｃｒ－０．０５Ｚｒ经时效处理后，硬度提高一倍以上。铬改善了此类合金的热稳定性及硬化效应。     

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.