硬质合金相图热力学和扩散动力学数据库及其应用

发布时间：2018-05-31 13:20

本文选题：硬质合金 + 热力学　；参考：《中国材料进展》2015年01期

【摘要】：硬质合金是由难熔金属化合物和粘结相通过粉末冶金工艺制成的材料,它具有硬度高、耐磨、强度和韧性好、耐热、耐腐蚀等一系列优良性能。介绍了包含C-Co-Cr-W-Ta-Ti-Nb-N等元素的硬质合金热力学和动力学数据库。简述了热力学数据库中的热力学模型和优化计算,并以C-Cr-Ta三元系为例介绍了热力学优化计算的方法和步骤。所建立的硬质合金动力学数据库包含液相和fcc相不同元素的原子迁移参数。利用修正的Sutherland方程对液相的原子迁移参数进行了评估,而fcc相原子迁移参数是基于对实验测定数据和文献数据的评估获得的。利用建立的硬质合金热力学和动力学数据库,可以计算多元系的相平衡、获取不同相的热力学性质和溶解度信息、模拟合金中元素和相的分布等。该数据库可用于设计合金成分和烧结温度、预测元素含量及烧结气氛等对梯度硬质合金形成的影响、优化合金烧结工艺等。最后指出相图热力学和扩散动力学数据库及热物性数据库结合相场、有限元方法,定量描述硬质合金结构-性能的关系是今后的发展趋势。
[Abstract]:Cemented carbide is made of refractory metal compounds and bonded phase through powder metallurgy process. It has a series of excellent properties such as high hardness, wear resistance, strength and toughness, heat resistance, corrosion resistance and so on. A database of thermodynamics and kinetics of cemented carbides containing C-Co-Cr-W-Ta-Ti-Nb-N and other elements is introduced. The thermodynamic model and optimization calculation in thermodynamics database are briefly introduced, and the method and procedure of thermodynamic optimization calculation are introduced by taking C-Cr-Ta ternary system as an example. The kinetic database of cemented carbide consists of atom migration parameters of different elements in liquid phase and fcc phase. The modified Sutherland equation is used to evaluate the atomic transport parameters of liquid phase, while the fcc phase atomic transport parameters are based on the evaluation of experimental data and literature data. By using the thermodynamics and dynamics database of cemented carbide, the phase equilibrium of the multicomponent system can be calculated, the thermodynamic properties and solubility information of different phases can be obtained, and the distribution of elements and phases in the alloy can be simulated. The database can be used to design alloy composition and sintering temperature, predict the effect of element content and sintering atmosphere on the formation of gradient cemented carbide, and optimize the sintering process of the alloy. Finally, it is pointed out that the relationship between structure and properties of cemented carbides can be quantitatively described by combining phase field and finite element method with thermodynamics and diffusion dynamics database of phase diagram and thermo-physical database.
【作者单位】：中南大学粉末冶金国家重点实验室;中德微结构联合实验室;株洲钻石切削刀具股份有限公司;
【基金】：国家自然科学基金资助项目(51371199,51474239,51371201) 工业信息化部“高档数控机床与基础制造装备”科技重大专项(2015ZX04005008) 中德科学中心资助项目(GZ755) 科技部“973”计划项目(2011CB610401,2014CB644002) 中南大学“升华学者”特聘教授启动基金中南大学中央高校基本科研业务费专项资金(2014zzts022)
【分类号】：TG135.5;TP311.13

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