Analysis of solidification microstructures during wedge-casting
Analysis of solidification microstructures during wedge-casting
复制标题
DOI：
10.1080/14786430500404116
复制
发表时间：
2006-08-21
影响因子：
1.6
通讯作者：
Hildal, K.
中科院分区：
文献类型：
--
作者：
Perepezko, J. H.;Hildal, K.
凝固组织演变是合金成分和热历史的函数。使用楔形模具，铸件可以在单次运行中经受不同数量级的冷却速率范围，通常为10（1）-10（3）K/s。结合微观组织分析、淬火熔体温度测量和传热分析，楔块铸造是探索合金凝固组织谱的有效和灵活的技术。在目前的研究中，楔形铸造技术的效用，开发检查块体玻璃形成合金相选择竞争和临界冷却速率条件下，通过结合多个热探针与基于测量的动力学分析。基于直接的热测量，微观结构分析和动力学建模，很明显，通常报告的单一的临界冷却速率的大块玻璃的形成应修改，包括一个临界冷却速率范围，以占成核控制的行为。此外，在比较玻璃形成合金的玻璃形成的相对容易性方面，有必要考虑相对热流特性以及相对成核动力学。
Solidification microstructure evolution is a function of both alloy composition and thermal history. With a wedge-shaped mold, castings can be subjected to a range of cooling rates differing by orders of magnitude, typically 10(1)-10(3) K/s, in a single run. Combining microstructure analysis, temperature measurements of the quenching melt and heat transfer analysis, wedge casting is an effective and flexible technique to explore the spectrum of alloy solidification microstructures. The utility of the wedge-casting technique is, in the current study, developed to examine bulk glass-forming alloys by combining multiple thermal probes with a measurement-based kinetics analysis of the phase selection competition and critical cooling rate conditions. Based upon direct thermal measurements, microstructural analysis and kinetics modelling, it is evident that the usual report of a single critical cooling rate for bulk glass formation should be modified to include a critical cooling rate range in order to account for nucleation controlled behavior. Furthermore, in comparing glass-forming alloys in terms of relative ease of glass formation, it is necessary to consider the relative heat flow characteristics as well as the relative nucleation kinetics.