含Mg GH3625合金在不同冷却速率下凝固过程中组织和析出相变的原位观察
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第一作者：张宇
通讯作者：龚伟
合写作者：李星彤,王鹏飞
发表刊物：国际钢铁研究
DOI码：10.1002/srin.202400301
刊物所在地：德国
摘要：In practical applications, intermetallic compounds like Laves phase and metal carbides adversely affect the performance of nickel-based superalloys. Using a high-temperature confocal laser scanning microscope, the solidification process of as-cast GH3625 alloy containing Mg at different cooling rates (-20, -35, and -50 °C min-1) is studied. Fitting curves of the volume fraction of the solid phase with solidification temperature before and after Mg treatment are obtained. Trends of solid phase transformation rates with solidification temperature are determined. Differential scanning calorimetry is employed to analyze and statistically evaluate the melting temperature range and enthalpy of each phase during the melting process. Experimental results demonstrate that Mg treatment significantly accelerates the alloy solidification at the cooling rates of -20 and -35 °C min-1, while reducing the area of residual liquid phase at the same solidification temperature, disrupting the Laves/NbC eutectic relationship, and regularizing NbC morphology, transitioning its distribution from aggregation to dispersion. After Mg treatment, the precipitation of the Laves phase is significantly reduced. As a result, the influence mechanism of Mg treatment on the phase transformation and microstructure of GH3625 is clarified based on homogeneous nucleation theory.
项目来源：国家自然科学基金面上项目
关键字：cooling rates, GH3625 superalloy, in situ observations, Mg treatment,
solidification structure
论文类型：SCI JCR Q2
学科门类：工学
文献类型：JCR 二区
一级学科：冶金工程
页面范围：1-14
ISSN号：1611-3683
是否译文：否