激光熔覆Inconel 625合金动态剪切响应及微观组织演变  

Dynamic shear response and microstructural evolution of laser-cladding Inconel 625 alloy

作　　者：刘涛 李思悦 雷经发 王璐 沈朝阳 LIU Tao;LI Siyue;LEI Jingfa;WANG Lu;SHEN Zhaoyang(School of Mechanical and Electrical Engineering,Anhui Jianzhu University,Hefei 230601,China;Anhui Education Department Key Laboratory of Intelligent Manufacturing of Construction Machinery,Hefei 230601,China)

机构地区：[1]安徽建筑大学机械与电气工程学院,合肥230601 [2]工程机械智能制造安徽省教育厅重点实验室,合肥230601

出　　处：《航空材料学报》2025年第2期28-36,共9页Journal of Aeronautical Materials

基　　金：安徽省高等学校自然科学研究重大项目(2023AH040036);安徽高校协同创新项目(GXXT-2023-025);合肥市自然科学基金资助项目(HZR2432)。

摘　　要：开展激光熔覆Inconel 625(IN625)合金动态剪切力学特性及微观结构演化规律的研究,可以为材料力学性能优化提供理论指导。采用分离式霍普金森压杆(SHPB)对激光熔覆IN625合金开展不同环境温度(20、600、800℃和1000℃)和加载应变率(40000、60000 s^(-1)和80000 s^(-1))下动态剪切实验,获得动态剪切应力-应变关系。结合扫描电镜(SEM)和电子背散射衍射(EBSD)对加载前后材料的微观形貌和晶体结构进行表征。结果表明:激光熔覆IN625合金应变率强化效应和温度软化效应显著,高温下温度软化效应主导材料力学行为。相比于未加载试样,常温动态剪切实验使材料呈现明显的剪切织构,位错密度升高,平均晶粒尺寸减小,小角度晶界占比由29%增至85%。与常温加载相比,高温动态剪切实验使材料晶体择优取向强度和位错密度均降低,平均晶粒尺寸进一步减小,小角度晶界占比由85%降至73.5%。It provides theoretical guidance for the optimization of mechanical properties to research the dynamic shear mechanical properties and microstructural evolution law of laser-cladding Inconel 625(IN625)alloy.A series of dynamic shear experiments are conducted using the split Hopkinson pressure bar(SHPB)at varying ambient temperatures(20,600,800℃and 1000℃)and strain rates(40000,60000 s^(−1) and 80000 s^(−1)).These experiments aim to establish the dynamic shear stress-strain relationship.Pre-and post-loading morphologies and crystal structures of the alloy are characterized using scanning electron microscopy(SEM)and electron backscatter diffraction(EBSD).The results show that both the strain rate strengthening effect and temperature softening effect are pronounced in laser-cladding IN625 alloy,with temperature softening effect predominantly influencing its mechanical behavior at elevated temperatures.Compared to the unloaded sample,the dynamic shear test at room temperature lead to the development of a prominent shear texture,with an increase in dislocation density and a decrease in average grain size.Specially,the proportion of small-angle grain boundaries increases from 29%to 85%.Conversely,high-temperature dynamic shear experiments,compared to room temperature loading,weaken the preferred orientation and reduce the dislocation density of the crystals.These high-temperature conditions further decrease the average grain size and lower the proportion of small-angle grain boundaries from 85%to 73.5%.

关 键 词：激光熔覆 IN625合金 动态剪切 微观组织 

分 类 号：V252.2[一般工业技术—材料科学与工程] O347.3[航空宇航科学与技术—航空宇航制造工程]