激光快速熔炼TC25G-TiAl4822梯度成分合金凝固组织演变行为  

Microstructure evolution behavior of gradient composition alloy between TC25G and TiAl4822 prepared by laser rapid melting

作　　者：王洋[1,2,3,4] 冉先喆 苏磊 孔德智博[1,2] 程序 李卓 刘栋 WANG Yang;RAN Xianzhe;SU Lei;KONG Dezhibo;CHENG Xu;LI Zhuo;LIU Dong(School of Materials Science and Engineering,Beihang University,Beijing 100191,China;National Engineering Laboratory for Additive Manufacturing of Large Metal Components,Beihang University,Beijing 100191,China;Ningbo Institute of Innovation,Beihang University,Ningbo 315800,Zhejiang,China;AVIC International Holding Corporation,Beijing 100027,China;Frontier Science and Technology Innovation Research Institute,Beihang University,Beijing 100191,China)

机构地区：[1]北京航空航天大学材料科学与工程学院,北京100191 [2]北京航空航天大学大型金属构件增材制造国家工程实验室,北京100191 [3]北京航空航天大学宁波创新研究院,浙江宁波315800 [4]中国航空技术国际控股有限公司,北京100027 [5]北京航空航天大学前沿科学技术创新研究院,北京100191

出　　处：《材料工程》2025年第3期95-104,共10页Journal of Materials Engineering

基　　金：国家科技重大专项(2019-Ⅶ-0003-0143);国家自然科学基金项目(52090044)。

摘　　要：未来高推重比先进航空发动机的发展对新型高性能轻质高温压气机整体叶盘需求迫切。激光增材制造TC25GTiAl4822双金属梯度结构材料作为轻质高压压气机整体叶盘备选的一种重要材料体系,其梯度过渡层合金的成分选择和凝固组织研究对指导相关构件结构性能设计具有关键影响。为理解(1-x)TC25G-xTiAl4822梯度成分合金随粉末原料中TiAl4822预合金粉末含量变化而出现的凝固组织演变行为,利用激光快速熔炼技术制备了两种单一原料(TC25G和TiAl4822)成分合金锭和9种混合原料成分合金锭,并采用光镜、扫描电镜、XRD和透射电镜等材料表征设备和硬度测量装置进行研究。研究结果表明:随原料中TiAl4822合金粉末含量的增加,合金凝固晶粒特征变化为树枝晶→等轴晶→树枝晶。合金室温显微组织发生如下的转变:α_(p)+α_(s)+β+α_(2)→α_(p)+α_(s)+α_(2)+β/B2→α+α_(2)+β/B2→α_(2)+B2→γ+γ/α_(2)+B2→γ+γ/α_(2);由于不同成分合金中的相类型和含量变化,合金维氏硬度值呈先增加后减小的变化趋势,且在粉末比例为50%~70%时具有极大突变,硬度由620HV降到450HV。上述相关研究结果为双金属过渡层合金的成分选择需避开中间比例粉末含量范围提供了基础依据。The development of advanced aero-engines with high thrust-to-weight ratios in the future has an urgent need for new high-performance lightweight high-temperature compressor blisks.Laser additive manufacturing TC25G-TiAl4822 gradient structure material is an important material system for the blisk of the lightweight high-temperature compressor.The composition selection and solidification structure research of gradient transition layer alloy have a key influence on guiding the structural performance design of related components.To understand the solidification structure evolution behavior of(1-x)TC25GxTiAl4822 transition layer alloy with the change of TiAl4822 pre-alloyed powder content in powder raw materials,two kinds of single raw material(TC25G or TiAl4822)alloy ingots and alloy ingots with nine kinds of mixed raw materials are prepared by laser melting technology.Material characterization equipment and hardness measurement devices such as optical microscope,scanning electron microscope,XRD,and TEM are used for the study.The research results show that with the increase of the content of TiAl4822 alloy powder in the raw material,the characteristics of solidified grains change to dendrite→equiaxed→dendrite.The microstructure of the alloy at room temperature changes as follows:α_(p)+α_(s)+β+α_(2)→α_(p)+α_(s)+α_(2)+β/B2→α+α_(2)+β/B2→α_(2)+B2→α_(2)+γ+B2→α_(2)+γ.Due to the change of the phase content of different alloy compositions,the Vickers hardness of the matrix first increases and then decreases,the overall hardness value changes in the range of about 450-620HV when the powder proportion is 50%-70%.If the intermediate composition alloy is directly used as the transition layer,the hardness will suddenly change.Therefore,the selection of the transition layer alloy composition should consider the range close to pure TC25G or TiAl4822.The above results provide the basis for the composition selection of bimetallic transition layer alloys to avoid the intermediate proportion of powder con

关 键 词：激光熔炼技术 梯度成分合金 凝固组织 相演变 硬度转变 

分 类 号：TB31[一般工业技术—材料科学与工程] TG146.23[金属学及工艺—金属材料]