铸型正反转搅动对精密铸造K4169合金凝固组织和室温力学性能的影响  

Effect of the Mold Positive and Negative Rotation on the Microstructure and Room-Temperature Mechanical Properties of K4169 Superalloy

作　　者：陈诚 杨光昱[1] 金梦辉 王强 汤鑫 程会民 介万奇[1] CHEN Cheng;YANG Guangyu;JIN Menghui;WANG Qiang;TANG Xin;CHENG Huimin;JIE Wanqi(State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi'an 710072,China;Key Laboratory of Advanced High Temperature Structural Materials,AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Xi'an North Optoelectronics Technology Defense Co.Ltd.,China North Industries Group Corporation Limited,Xi'an 710043,China)

机构地区：[1]西北工业大学凝固技术国家重点实验室,西安710072 [2]中国航发北京航空材料研究院先进高温结构材料重点实验室,北京100095 [3]中国兵器工业集团西安北方光电科技防务有限公司,西安710043

出　　处：《金属学报》2024年第7期926-936,共11页Acta Metallurgica Sinica

基　　金：国家科技重大专项项目No.J2019-VI-0004-0118。

摘　　要：为揭示离心铸造工艺在晶粒细化和力学性能提升等方面的优势,本工作对比分析了铸型正反转搅动动力学细晶法离心铸造工艺和常规重力铸造工艺条件下K4169合金典型结构特征件的凝固组织和室温力学性能,研究了2种工艺条件下得到的合金组织、元素偏析、第二相分布以及断口组织形貌和室温力学性能。结果表明,铸型正反转搅动处理可使K4169合金铸态组织明显细化,当铸型正反转持续时间为4 s时,K4169合金的晶粒组织细化效果显著,晶粒尺寸从重力铸造工艺下的(5.37±0.21) mm减小至(0.27±0.01) mm;铸造K4169合金的初生相破碎,枝晶形貌退化,合金元素偏析程度减轻,凝固组织中Laves相数量减少,碳化物数量略有增加;铸型正反转4 s条件下,铸态合金的室温抗拉强度比重力铸造条件下提高了31.4%。The service temperature of K4169 superalloy aeronautic turbine disks and other important aeronautic components is generally below the equi-strength temperature,and grain refinement can significantly improve the service performance.Compared with the conventional gravity casting process,the centrifugal casting process as a dynamic grain refinement method plays an important role in grain refinement,feeding,and molten filling of the casting.A precision casting with typical structural characteristics of the K4169 superalloy was prepared using the centrifugal casting process with the mold positive and negative rotation method and the conventional gravity casting process,respectively.The alloy microstructure,element segregation,secondary phase distribution,fracture microstructure,and mechanical properties at room temperature were compared and studied under two process conditions.The as-cast structure of the K4169 superalloy can be significantly refined using the mold positive and negative rotation method.The grain refinement of the experimental alloy was the most significant when the casting mold was reversed for 4 s,and the grain size under gravity casting decreased from(5.37±0.21)mm to(0.27±0.01)mm.Also,the primary phase of the experimental alloy was broken and the dendrite morphology was degraded that the coarse dendrites were replaced by broken dendrites and rose-shaped crystals after positive and negative rotations.Compared with unidirectional rotation,the segregation of alloying elements decreased,the number of Laves phases in the solidified structure was reduced,and the number of carbides was slightly increased.The tensile strength of the K4169 alloy at room temperature under the positive and negative rotation duration of 4 s was 31.4%higher than that under conventional gravity casting.

关 键 词：K4169合金 铸型正反转 熔模铸造 凝固组织 室温力学性能 

分 类 号：TG249.4[金属学及工艺—铸造]