单晶高温合金DD3的相特征

Phase Characteristics of DD3 Single Crystal Superalloy

利用物理化学相分析方法研究第一代单晶高温合金DD3的相特征。通过相萃取分析热处理前后γ′相和碳化物相的组成、含量及其结构式,并对比分析不同状态下DD3合金的强化相粒度、基体相成分及元素分配行为的变化。热处理前后的相特征分析表明,热处理不仅提高DD3合金γ′相含量、减小γ′相粒度,还改变合金元素的分配行为,提高γ′相的强度和稳定性。热处理的过程是γ′相得到强化的过程。

The characteristics of DD3 single crystal superalloy were investigated with physicochemical phase analysis method. Chemical compositions,mass fractions and approximate formulas of γ′ phase and carbides in DD3 single crystal superalloy as cast and heat treatment condition were determined with Phase Extraction method. γ′ sizes, chemical compositions of matrix and partition ratios of γ′/γ were analyzed and calculated from the result of electrochemical extracting of the precipitates. The comparison of phase characteristics of DD3 as cast and heat treatment show that heat treatment increases the mass fraction, decreases the size of γ′, and changes the phase composition and partition behavior of elements. As a result, the strength and stabilization of γ′ are improved with heat treatment.