摘要
A combination of casting and laser remelting was employed to develop a high-strength and heat-resistant Al-Si-Fe alloy suitable for powder bed fusion using a laser beam(PBF-LB).By clarifying the effects of the incorporated elements and their contents on the microstructure and mechanical performance of Al-Si-Fe alloys,the composition was optimized as Al-11Si-2.5Fe-2Mn-1.2Ni-0.4Cr(in wt.%).The optimized alloy was subsequently validated using PBF-LB,which exhibited favorable machinability,achieving a density of 99.8%.The room-temperature tensile strength of the PBF-LB manufactured Al-Si-Fe alloy reached(512.76±3.26)MPa,with a yield strength of(337.79±2.36)MPa and an elongation of(2.98±0.07)%.The enhanced room-temperature mechanical properties could be mainly attributed to the combined effects of fine-grain strengthening,solid solution strengthening,and precipitation strengthening.At 300°C,the high-temperature tensile strength of the developed alloy reached(222.47±6.41)MPa,with a yield strength of(164.25±11.40)MPa and an elongation of(8.88±0.33)%,outperforming those of existing alloys documented in the literature.The improved high-temperature mechanical performance was primarily provided by the three-dimensional network comprising cellular heat-resistant Al17(FeMnNiCr)4Si2 andα-Al(FeMn)Si phases.
采用铸造和激光重熔相结合的方法,开发出一种适于激光粉末床熔融(PBF-LB)成形的高强耐热Al-Si-Fe合金。通过分析所添加合金元素的种类及含量对Al-Si-Fe合金显微组织和力学性能的影响,优选出一种Al-11Si-2.5Fe-2Mn-1.2Ni-0.4Cr(质量分数,%)合金成分。随后,采用PBF-LB对所优选的合金开展成形验证,其密度达到99.8%,表现出良好的成形性能。PBF-LB成形Al-Si-Fe合金的室温抗拉强度达到(512.76±3.26)MPa,屈服强度为(337.79±2.36)MPa,伸长率为(2.98±0.07)%;材料室温力学性能的提高主要归因于细晶粒强化、固溶强化和析出强化的综合作用。所开发合金在300℃的高温抗拉强度达到(222.47±6.41)MPa,屈服强度为(164.25±11.40)MPa,伸长率为(8.88±0.33)%,优于现有文献中合金的相应性能;高温力学性能的提高主要得益于由呈蜂窝状分布的Al17(FeMnNiCr)4Si2和α-Al(FeMn)Si耐热相组成的三维网络结构。
基金
supported by the National Natural Science Foundation of China(Nos.52375393,52071299)
the Science and Technology Innovation Talent Team of Shanxi Province,China(No.202304051001029)
the Scientific and Technological Achievements Transformation Guidance Project of Shanxi Province,China(No.202204021301048)
the Key R&D Program of Shanxi Province,China(Nos.2210300058MZ,202202150401020)
the Hai’an&Taiyuan University of Technology Advanced Manufacturing and Intelligent Equipment Industrial Research Institute,China(No.2023HA-TYUTKFYF020)
the Young Elite Scientists Sponsorship Program by CAST,China(No.2023QNRC001).
