含钛低碳钢凝固过程中氧化钛形成的热力学

通过研究含钛低碳钢的热力学,确定了在凝固过程中形成氧化钛的最佳钢液条件。计算结果表明：在含钛低碳钢中,为促进凝固初期析出Ti2O3从而细化凝固组织,关键的工艺要点是控制钢液中氧含量在0．0005％～0．0030％,铝含量小于0．001％,氮含量小于0．014％。     

钛合金铸件铣削工艺

分析了钛合金铣削过程中刀具磨损的原因和机理，并提出了减少刀具磨损的方法和措施及工艺参数，以提高刀具的寿命和工件质量。     

Formation of Titanium Boride in the Surface Layer of an Iron–Carbon Alloy Casting

The main stages of titanium boride formation in alloyed surface layers on iron–carbon alloy castings are considered. Surface alloying was performed by self-propagating high-temperature synthesis in alloying compositions during lost-foam casting. Titanium and ferrotitanium are used in alloying compositions to ensure synthesis, which is initiated by the melt thermal energy during casting formation. The thermal effects of the main reactions of titanium boride formation in various alloying compositions are compared. The microstructure, the phase composition, and the hardness of the alloyed surface layers are studied.     

The Effect of Heating Rate on Discontinuous Grain Boundary Alpha Formation in a Metastable Beta Titanium Alloy

Metallurgical and Materials Transactions A - Continuous grain boundary α ( $$ \alpha_{\text{GB}} $$ ) is often observed in age-hardened metastable β titanium alloys and plays a...     

钛白粉直接合金化制备钛铝合金理论及工艺研究

对铝热还原工艺制备钛铝合金的热力学进行计算与分析,探索了配石灰系数(即理论用量的倍数)及单位热效应对钛收率的影响,并分析了配铝系数对合金中钛和铝的影响以及影响钛铝合金中氧含量的因素。结果表明,最佳工艺参数为:配石灰系数0.9,单位热效应2 850kJ/kg。     

Hydrogen Transport and Rationalization of Porosity Formation during Welding of Titanium Alloys

The transport of hydrogen during fusion welding of the titanium alloy Ti-6Al4V is analyzed. A coupled thermodynamic/kinetic treatment is proposed for the mass transport within and around the weld pool. The modeling indicates that hydrogen accumulates in the weld pool as a consequence of the thermodynamic driving forces that arise; a region of hydrogen depletion exists in cooler, surrounding regions in the heat-affected zone and beyond. Coupling with a hydrogen diffusion-controlled bubble growth model is used to simulate bubble growth in the melt and, thus, to make predictions of the hydrogen concentration barrier needed for pore formation. The effects of surface tension of liquid metal and the radius of preexisting microbubble size on the barrier are discussed. The work provides insights into the mechanism of porosity formation in titanium alloys.     

铸钛工业与机电一体化技术

介绍了我国铸钛工业技术的发展进程和现状，并结合目前国内用于工业牛产的最大容量（260kg）真空白耗电极电弧凝壳炉，对工艺、设备、系统硬件、软件等方面采用机电一体化技术的情况进行了说明，阐述了机电一体化技术应用于铸钛工业，对提高铸件熔炼工艺水平、保证铸件产品质量和提高铸钛工业的总体竞争力，及促进整个铸钛工业技术水平的发展进步所具有的重要意义。     

铸造铝硅合金中硅相变质机制的电子理论研究

通过计算机编程构造出了Al-Si铸造合金中Si(金刚石结构)相(111)表面及稀土导致的(111)孪晶表面的原子结构模型，利用连分敷方法计算了稀土处于表面及孪晶表面这两种位置时的电子结构。稀土原子处于孪晶表面时的结构能明显比处于Si(111)表面大，说明稀土原子容易占据孪晶表面的位置；稀土原子处于孪晶界时的环境敏感镶嵌能比处于表面小，说明稀土处于孪晶表面时比较稳定，同时原子间的键级积分计算也表明稀土能够占据孪晶表面的位置且在此处较稳定。这就从电子层次解释了稀土导致孪晶的事实，阐明了稀土在Al-Si铸造合金中的变质机制。     

Thermodynamic Evaluation of Inclusions Formation and Behaviour in Steels during Casting and Solidification

For demanding applications high steel cleanliness and strictly controlled inclusions are required. Primary inclusions are formed during steel treatments in the ladle. Most of these are removed to the ladle slag or on the lining. However, the rest of the inclusions still remain through the successive process stages, and additionally new inclusions are formed during casting and solidification due to decreasing thermodynamic solubility of oxygen in the steel at lower temperatures, reactions with surrounding slag, refractory materials and eventual contact with air. Inclusions formation and transformation are simulated by thermodynamic calculations in the steel/inclusions/slag system taking into account the solidification phenomena. In this paper inclusions in Si/Mn‐deoxidised steel and Al‐deoxidised Ca‐treated steels are contributed. Calculations are compared with experimental results from steel plants.     

Theoretical Model of Steel Continuous Casting Technology

 A theoretical model adapted for studying steel continuous casting technology was proposed. The model based on system theory contained input/output, command, and control parameters. The process was divided into five stages, ie, tundish, mold, guiding system, guiding drawing system, and guiding drawing soft reduction system. The model can be used to describe the physicochemical processes, thermal processes, chemical processes, and characteristics of the cast material according to the above mentioned stages. It can also be applied to other metallurgical technologies and even to other industries (chemistry, food, etc).     

Formation of Titanium Sulfide from Titanium Oxycarbonitride by CS2 Gas

Metallurgical and Materials Transactions B - Previously this group reported that a good quality titanium metal powder can be produced from titanium sulfides by electrochemical OS process. In this...     

Effect of Substrate Temperature on Structure Formation in Titanium Alloy during Direct Laser Deposition

Metallurgist - The paper analyzes the effect of substrate temperature on the shape, size, and orientation of grains in the structure of VT6 alloy samples formed by the method of direct laser...     

钛精铸高尔夫球头的现状及发展趋势

综述了钛精铸高尔夫球头和普通石墨型高尔夫球头的发展动态，以及国外普通钛及钛合金铸件的现状和发展趋势。对国内主要精铸钛合金高尔夫球头商家及其特点，市场现状进行了分析预测。     

海绵钛中残留氯化镁对钛及钛合金熔铸的影响

分析了海绵钛残留氯化镁对钛及钛合金熔铸的影响。在钛及钛合金铸锭生产过程中,由于氯化镁吸湿现象导致压制的电极块出现白色析出物、一次锭表面有潮湿的黑斑以及真空系统内沉积物水化等现象。残留氯化镁对真空熔炼及设备的危害主要有:①增大发气量,降低熔炼真空度;②使铸锭气体杂质含量偏高,气孔增加;③使铸锭中残留的高熔点颗粒增加;④腐蚀真空系统,降低设备寿命。最后对出现的问题,提出了相应的预防措施。     

钛白后处理中TiO2浆料分散性优化试验研究

分别从分散剂种类、数量、加入方式3个方面进行优化试验,均加入钛白初品中打浆分散。所有的打浆分散的时间都为15min,转速都在2000r／min。对上述3种浆液采用沉降法测定其分散性,分别获得了最佳分散剂种类为六偏磷酸钠、最佳分散剂数量为0．1％～0．3％、最佳加入方式为分散前加入的优化参数。     

Mechanism of Macrosegregation Formation in Continuous Casting Slab: A Numerical Simulation Study

Metallurgical and Materials Transactions B - Solidified shell bulging is supposed to be the main reason for slab center segregation, while the influence of thermal shrinkage rarely has been...