钛制机动艇船台

研究了配碳量与Ｎｉ／Ｃｏ比对ＷＣ－９（Ｎｉ－Ｃｏ）硬质合金抗率强度的影响。实验结果表明：ＷＣ－３Ｎｉ－６Ｃｏ的配碳量是６．０４ｗｔ％时，其抗弯强度与ＷＣ－９Ｃｏ硬质合金相当；Ｎｉ的分布均匀性对抗弯强度的影响极其重要，粗粒Ｎｉ粉或（和）较多η相的存在都会使硬质合金形成脆性断裂，直接影响合金的抗弯强度。     

WC—Co硬质合金热处理后的TEM观察

对ＹＧ１１Ｃ和ＹＧ１３Ｃ两种牌号硬质合金热处理后的微观组织进行了ＴＥＭ分析，通过电子衍射花样的标定，确认了ＣｏｘＷｙＣｚ物相在淬火回火所得的面心立方钴（α－Ｃｏ）中的存在，并结合硬质合金热处理前后抗弯强度的测定，其该类物相在面心立方钴中的作用进行了初步探讨，结果表明：ε－Ｍ，Ｃｏ３Ｗ，Ｃｏ７Ｗ６，ｋ－Ｃｏ３Ｗ９Ｃ４等物相在热处理后的硬质合金中可起的强化作用，从而提高硬质合金的抗弯强度。     

WC—8（Fe／Ni／Co）R硬质合金的研究

用Ｆｅ、Ｎｉ部分取代ＷＣ－８Ｃｏ合金（牌号ＹＧ８）中的粘结剂Ｃｏ,再添加微量稀土Ｒ制得ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金,测试了其物理机械性能,研究了粘结剂各种成份比例及烧结温度对硬质合金的影响。结果表明：ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ硬质合金的性能可以达到ＹＧ８的性能标准。利用扫描电镜（ＳＥＭ）及Ｘ射线衍射（ＸＲＤ）对其作了显微结构分析,同时探讨了影响ＷＣ－８（Ｆｅ／Ｎｉ／Ｃｏ）Ｒ合金性能的     

WC—Co硬质合金的饱和磁化强度

探讨了ＷＣ－Ｃｏ硬质合金饱和磁化强度的影响因素、磁化机制和比饱和磁化强度４πσ与抗弯强度σ（ＴＲＳ）的关系。结果表明，影响ＷＣ－Ｃｏ合金４πσ的主要因素是γ相含量和γ相成分，其次是γ相结构。其４πσ同合金标称钴含量或合金碳含量间均不存在单一性对应关系。γ相分布和热处理及添加稀土元素对合金４πσ的影响，实质上仍归结为上述基本因素的作用。ＷＣ－Ｃｏ合金的４πσ同抗弯强度间并不存在明确的对应关系，因而难以用饱和磁化强度（Ｍｓ或４πσ）取代σ（ＴＲＳ）的测定。     

Co含量对（WC—Co／NiCrBSi）复合钎焊涂层耐磨性的影响

采用真空钎焊技术,将ＷＣ－Ｃｏ硬质合金粉和ｉＣｒＢＳｉ（ＡＷＳ ＢＮｉ－２）合金粉钎焊到４５＃钢表面,得到（ＷＣ－Ｃｏ／ｎｉＣｒＢＳｉ）复合钎焊涂层。在不同钎焊工艺下,涂层自身 和层／基体间的拉伸结合强度分别达（１００－１４０）ＭＰａ和（３００－３６０）ＭＰａ。研究了Ｃｏ含量对（ＷＣ－Ｃｏ／ＮｉＣｒＢＳｉ）复合涂层磨损性能的影响。实验结果表明（ＷＣ－Ｃｏ／ＮｉＣｒＢＳｉ）复合涂层磨损性能高于同配比     

WC—CoWC—NiWC钎焊涂层耐磨性研究

采用真空钎焊工艺,交硬质合金粉（ＷＣ－Ｃｏ,ＷＣ－Ｎｉ,ＷＣ）及钎焊合金（ＮｉＣｒＢＳｉ）焊到４２ＣｒＭｏ钢基体表面,研究了不同硬质全金粉对钎焊涂层抗磨料磨损性能的影响,初步分析了涂层磨损机制。     

WC（15—20）m?—Co—Ni硬质合金研究

研究了富铁的高粘结剂ＷＣ基硬质合金,其基本化学成分为ＷＣ－（１５－２０ｍ％）（Ｆｅ－１９％Ｃｏ－１６％Ｎｉ）,根据ＷＣ粉原始颗粒度等的不同,试制了４种硬质合金,其物理机械性能均达到或相当地相应牌号ＷＣ－Ｃｏ基硬质合金的水平,对２０％粘结相的２种硬质合金做了应用试验,均取得了满意的使用效果。     

用磁性法测定两相WC－Co硬质合金的碳含量

论述了用４πσ测定两相ＷＣ－Ｃｏ硬质合金碳含量的方法和原理。结果表明，用４πσ鉴定ＷＣ－Ｃｏ合金碳含量的两相区范围作为质量控制目的切实可行。由于影响４ｎσ的因素较多，精确测定ＷＣ－Ｃｏ合金两相区内碳含量需要预先确定试样的结构状态，并作出相应状态下的合金４πσ－Ｘｃ校准曲线，测定精度为万分之二。     

四元扩散偶技术及其在相图研究中的应用（Ⅱ）Mo－Fe－Ni和Mo－Ni－Co三元系在1200℃时的相平衡

采用一个Ｍｏ－Ｆｅ－Ｎｉ－Ｃｏ四元扩散偶试样，测定了Ｍｏ－Ｆｅ－Ｎｉ和Ｍｏ－Ｎｉ－Ｃｏ在１２００℃时的两个三元系等温截面；并借助金相显微镜、扫描电镜能谱仪以及电子探针，确定了Ｍｏ－Ｆｅ－Ｎｉ三元系在１２００℃时三元合金中三元化合物Ｐ相的存在。该系统中存在ｂｃｃ（Ｍｏ）、μ－Ｆｅ７Ｍｏ６、δ－ＭｏＮｉ、ｂｃｃ（Ｆｅ）、ｆｃｃ和Ｐ六个单相区；在Ｍｏ－Ｎｉ－Ｃｏ三元系中存在ｂｃｃ（Ｍｏ）、δ－ＭｏＮｉ、μ－Ｃｏ７Ｍｏ６和ｆｃｃ四个单相区。     

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．     

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.