航空材料学报2025，Vol.45Issue(1)：70-79,10.DOI:10.11868/j.issn.1005-5053.2023.000014
浇注温度对DD419单晶高温合金组织及持久性能的影响
Effect of pouring temperature on microstructure and durability of DD419 single crystal superalloy
摘要
Abstract
The creep rupture properties of DD419 single crystal superalloys,fabricated at varying pouring temperatures were examined under conditions of 850℃/650 MPa,1050℃/190 MPa and 1100℃/130 MPa.SEM,EDS and TEM were used to analyze the microstructure and component segregation to study their effects on the durability.The results show that as the pouring temperature decreases,the primary dendrite spacing of the alloy widens,the eutectic content and the number of micropore increase,and the γ′phase size diminishes.Under high temperature/low stress(1100℃/130 MPa),the γ′phase size exerts a more pronounced influence on durability than do micropore and residual eutectic content.The finely dispersed γ′phase enhances the alloy's durability under all three test scenarios,with the alloy poured at 1500℃exhibiting optimal durability.At intermediate temperature/high stress condition(1050℃/190 MPa),the γ′ phase is intersected by numerous dislocations,and dispersed γ′ phase may contribute to dislocation pile-ups.Concurrently,the alloy maintains good elongation at different pouring temperatures;however,as the pouring temperature decreases,section shrinkage decreases under all three test conditions.Pouring temperature has a negligible impact on the the alloy's fracture morphology.Specifically,the γ′ phase near the fracture surface of the specimen tested under 850℃/650 MPa condition remains cubic morphology,with a mixed-mode fracture mechanism.Under other durability parameters,the γ′ phase assumes a rafted configuration,leading to an all-micropore aggregation fracture mechanism.关键词
DD419/浇注温度/持久性能/显微孔洞/断裂机制Key words
DD419/pouring temperature/creep rupture property/micropore/fracture mechanism分类
航空航天引用本文复制引用
张辉,丁强,刘纪德..浇注温度对DD419单晶高温合金组织及持久性能的影响[J].航空材料学报,2025,45(1):70-79,10.基金项目
国家重点研发计划项目(2020YFA0714900) （2020YFA0714900）
