摘要
为了解决激光熔覆In718合金力学性能差的问题,选择不同的扫描速率对In718合金熔覆层进行了激光重熔处理,采用光学显微镜、扫描电镜和能谱仪观察显微组织结构和特征,检测不同物相的成分并分析微观偏析对显微组织的影响,通过力学检测设备对涂层的显微硬度与抗拉强度进行检测。结果表明,Laves相主要由Nb与Mo元素的偏析所导致,与未重熔相比,重熔后的涂层气孔明显减少,且不同的重熔扫描速率对组织与性能的影响也不同,4个涂层的Laves相体积分数由34.1%减少至24.6%、16.7%和19.6%,平均硬度由250.3 HV提高至261.5 HV、276.9 HV和268.0 HV,抗拉强度由678 MPa提高至728 MPa、879 MPa和808 MPa,而重熔对涂层延伸率的影响不明显;最优的重熔扫描速率为15 mm/s,Laves相的体积分数最低,平均显微硬度和抗拉强度最高;激光重熔能有效改善熔覆层的形貌、降低孔隙率、减少或抑制Laves相的析出,并且减少Laves相有助于提高In718合金的力学性能。此研究为后续的离心球墨铸管模具的再制造奠定了理论基础。
In order to solve the problem of poor mechanical properties of laser cladding In718 alloy,different scanning speeds were selected to carry out laser remelting treatment of the cladding layer.Optical microscope,scanning electron microscope and energy dispersive spectrometer were used to observe the microstructure and characteristics and to detect the composition of different phases.The influence of microsegregation on the microstructure was then analyzed.The microhardness and tensile strength of the coating were tested by mechanical testing equipment.The results show that the Laves phase is mainly caused by the segregation of Nb and Mo elements.Compared with the non-remelted coating,the pores of the remelted coating are significantly reduced,and different remelting scanning speeds have different effects on the structure and properties.The Laves phase volume fraction of four coatings respectively decreased from 34.1%to 24.6%,16.7%,and 19.6%,the average hardness respectively increased from 250.3 HV to 261.5 HV,276.9 HV,and 268.0 HV.The tensile strength respectively increased from 678 MPa to 728 MPa,879 MPa,and 808 MPa.However,the effect of remelted coating on elongation is not obvious.The optimum remelting scanning speed is 15 mm/s,which has the lowest Laves phase content and the highest average microhardness and tensile strength.Laser remelting can effectively improve the morphology of the cladding layer,reduce the porosity,reduce or inhibit the precipitation of Laves phase.Reducing the Laves phase to improve the mechanical properties of In718 alloy.This research establishes a theoretical foundation for the subsequent remanufacturing of centrifugal cast ductile iron pipes molds.
作者
晁祥瑞
黄勇
陈子鹏
许学虎
李文建
王宁
张志虎
CHAO Xiangrui;HUANG Yong;CHEN Zipeng;XU Xuehu;LI Wenjian;WANG Ning;ZHANG Zhihu(School of Mechanical and Electrical Engineering,Xinjiang Agricultural University,Urumqi 830052,China;School of Mechanical and Electrical Engineering,Xinjiang Institute of Engineering,Urumqi 830023,China;Ductile Iron Pipes Fukang Energy Co.Ltd.,Changji 831500,China;Xinjiang Huixiang Laser Technology Co.Ltd.,Karamay 833699,China;Research Center of Laser Intelligent Manufacturing and Remanufacturing Engineering Technology,Xinjiang Institute of Engineering,Urumqi 830023,China)
出处
《激光技术》
CAS
CSCD
北大核心
2023年第4期506-512,共7页
Laser Technology
基金
新疆维吾尔自治区自然科学基金地州科学基金资助项目(2022D01F43)
新疆工程学院科研基金资助项目(2019xgy152112)
新疆工程学院育人基金资助项目(2019xgy182112)
新疆维吾尔自治区科协青年人才托举工程项目(RCTJ46)
新疆维吾尔自治区高校科研计划资助项目(XJEDU2019Y064)。
