摘要
非等原子比FeNiCoAlTaB高熵合金(NCATB)因其独特的元素组成展现出良好的工程应用潜力,然而传统加工工艺产生的元素偏析和晶界Ni Al相会损害其强度性能。因此,采用激光粉末床熔融(laser powder bed fusion,LPBF)技术结合低温时效处理,制备兼具强度和塑性的NCATB高熵合金,并系统研究了工艺参数对合金致密度、微观组织、应力状态及力学性能的影响规律。结果表明,适当的激光功率与扫描速度组合可有效减少成形缺陷并提高致密度;快速凝固引入大量位错结构,形成明显的织构与细化组织。通过热处理可促进γ′与B2析出相的形成,协同晶界演化,有效提升材料强度。研究表明,增材制造结合热处理工艺可实现NCATB合金的强塑协同调控,展现出优异的综合力学性能与良好的工程应用潜力。
Non-equiatomic FeNiCoAlTaB high-entropy alloys(NCATBs)exhibit promising engineering application potential due to their unique elemental composition.However,the element segregation and NiAl phase alone at the grain boundary generated by traditional processing techniques can compromise the strength properties of the material.On this basis,a non-equiatomic FeNiCoAlTaB high-entropy alloy(NCATB-HEA)with a balance of strength and ductility was fabricated via laser powder bed fusion(LPBF),followed by a 600℃low-temperature aging treatment.The effects of processing parameters on the densification,microstructure,residual stress,and mechanical properties of the alloy were systematically investigated.The results show that a proper combination of laser power and scan speed significantly reduces the number of defects and improves the density.Rapid solidification introduces a high density of dislocations and refines the grain structure with an evident texture.Heat treatment promotes the formation ofγ′and B2 precipitates,which synergistically evolve with grain boundaries to increase the alloy strength.This work demonstrates that the integration of additive manufacturing and heat treatment enables the coordinated strengthening and toughening of NCATB alloys,offering promising mechanical performance and engineering potential.
作者
孙沁瑶
杜大帆
彭望君
何林
董安平
赵凯
SUN Qinyao;DU Dafan;PENG Wangjun;HE Lin;DONG Anping;ZHAO Kai(Shanghai Key Lab of Advanced High-temperature Materials,Shanghai Jiao Tong University,Shanghai 200240,China;Precision Forming and State Key Lab of Metal Matrix Composites,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Aerospace Equipment Manufacturing General Factory Co.,Ltd.,Shanghai 200245,China)
出处
《铸造技术》
2025年第8期765-773,共9页
Foundry Technology
基金
上海市自然科学基金面上项目(23ZR148800)
国家自然科学基金(52474416)
航天八院-上海交大联合基金(USCAST2022-25)。
关键词
高熵合金
激光粉末床熔融
低温时效
微观组织演化
力学性能
high-entropy alloy
laser powder bed fusion
low-temperature aging
microstructural evolution
mechanical properties
作者简介
孙沁瑶,1998年生,博士生.研究方向为金属增材制造精密成型.Email:MSEQYSun@sjtu.edu.cn;通信作者:杜大帆,1987年生,副教授,博导.研究方向为高温合金精密成型.Email:dafand@sjtu.edu.cn;通信作者:董安平,1977年生,研究员,博导.研究方向为高温合金精密成型.Email:apdong@sjtu.edu.cn。
