熔体冷却速率与块体非晶合金塑性的关系研究

项目名称： 熔体冷却速率与块体非晶合金塑性的关系研究

项目编号： No.51204118

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 冶金与矿业学科

项目作者： 胡勇

作者单位： 太原科技大学

项目金额： 25万元

中文摘要： 非晶合金在室温变形过程中通常表现出较差的塑性，使其实际应用受到一定程度的影响，因此研究非晶合金的塑性变形机制具有重要的科学意义和工程应用价值。已有研究表明，增加原子结构的有序度或无序度都可以有效改善块体非晶合金的塑性。这意味着，相同成分块体非晶合金的塑性随着微观结构的变化并不是单调增加或减小，而是经历一个由高到低再升高的转变。但该推论是否成立，仍缺乏充足的实验依据。为此，本项目将通过控制熔体冷却速率制备具有不同微观结构的块体非晶合金，并对其进行变形，分析不同成分块体非晶合金塑性与冷却速率之间的关系。另外，人们目前对非晶合金塑性变形机制的认识还不是很清楚，尤其是具有单一结构的非晶合金。为此，本项目将主要采用透射电镜、X射线衍射和热分析，系统地研究熔体冷却速率与合金成分对微观结构的影响，建立熔体冷却速率、合金成分、微观结构与塑性之间的内在关系，试图从原子尺度上认识非晶合金的塑性变形机制。

中文关键词： 非晶合金；塑性变形；冷却速率；微观结构；

英文摘要： Metallic glasses often show worse plasticity during deformation in room temperature, which considerably confines its practical application. Therefore, it will have important scientific significance and engineering applications value to investigate the plastic deformation mechanism of metallic glasses. The existing results showed that the plasticity of bulk metallic glasses can be improved by increasing ordering or disordering degree. That is to say, the bulk metallic glasses with the same composition would experience a nonmonotonic change in plasticity while the microstructure goes from disorder to order, i.e., a transition of "large-small-large" in the plasticity. However, there are still not enough data to verify that such inference is right or not. Therefore, bulk metallic glasses will be prepared by controlling the cooling rates of melt and then be deformed in this project. Accordingly, a relationship between cooling rate and the plasticity of bulk metallic glasses with different composition will be analyzed. In addition, so far the deformation mechanism of metallic glasses is still not clear, especially for the metallic glasses with homogeneous structure. Therefore, the effect of cooling rate of melt and composition on the microstructure of bulk metallic glasses will be investigated by means of transmission

英文关键词： Metallic glass；Plastic deformation；Cooling rate；Microstructure；