B2型金属间化合物深过冷组织演化规律和高塑性机理

项目名称： B2型金属间化合物深过冷组织演化规律和高塑性机理

项目编号： No.51271073

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 郭学锋

作者单位： 河南理工大学

项目金额： 80万元

中文摘要： B2型金属间化合物（简称B2化合物）凝固组织结构缺陷类型（空位或反位原子）、微量元素偏析规律、第二相及分布对其韧塑性具有重要影响。考虑到组织与凝固历史相关，本研究用熔融玻璃净化结合循环过热深过冷快速凝固技术，研究深过冷态B2化合物组织演化规律、金属凝固生长模式；研究B2化合物不同过冷组织塑性特性，揭示其本征塑性。用深过冷技术研究严格（或偏离）化学计量成分的NiSc和CoSc两种均质单相B2化合物的制备机理。用组织观察和枝晶生长模型研究非平衡凝固下B2化合物的形核、枝晶生长和组织演化规律，丰富B2金属间化合物非平衡凝固理论。用电镜等分析手段研究非平衡态获得均质单相B2化合物的成分范围和化合物结构缺陷类型。用变形和变型激活能理论研究B2化合物非平衡组织本征塑性及不同应变速率下B2化合物变形机理。最终明晰B2化合物非平衡组织演化、生长模式、结构缺陷类型和本征塑性的关系。

中文关键词： 快速凝固；金属间化合物；B2结构；NiSc；枝晶生长

英文摘要： Structure defects, trace elements, constitution and quantity of secondary phases have significant effets on the ducility and plasticity of intermetallics with B2 structures (hereafter B2). All those microstructures mentioned above have more or less relationship to their solidificaiton histories. Therefore,preparation of sigle phase B2 is the key for this research.Undercooling technique is the most reasonable and effective method to synthesize sigle phase alloy with composition uniformity. Moreover, using this technique can not only prepare sigle phase alloy, but also can study microstructural evolution, dendritical growth model and intrinsical plasticity and ductility. Therefore, in this study we will prepare single phase NiSc and CoSc B2 intermetallics with composition uniformity by using a combinational processes of glass fluxing and cyclical-superheating undercooling technology. Firstly, we will follow strictly stoichiometric composition for the undercooling test, and also select nonstoichiometric compositions to prepare B2 in order to find out the compositional region in which single phase B2 can be prepared. Secondly,our research efforts will contribute to the study of nucleation, growth model and microstructure evolution using varaity of microstructure observation means and dendritic growth model. Thirdly,

英文关键词： Rapid solidification；Intermetallics；B2 structure；NiSc；Dendritic growth