摘要
采用搅拌摩擦辅助激光定向能量沉积方法制备了AlSi10Mg合金块体,采用后续冷轧处理进一步提高了AlSi10Mg合金的强度,系统讨论了AlSi10Mg合金在加工过程中的组织演化,分析了其强韧性的演变机理。研究结果表明:在激光沉积态AlSi10Mg合金中,Si原子的固溶强化效果非常显著,合金的硬度高达109 HV,受气孔缺陷影响,激光沉积AlSi10Mg合金的强度低于200 MPa。搅拌摩擦加工可以细化激光沉积AlSi10Mg合金的柱状α-Al相和共晶相,形成等轴的α-Al晶粒和Si颗粒,α-Al基体中的Si原子脱溶析出,其硬度降低至75 HV,强度接近200 MPa,延伸率最高达到40%。轧制后,AlSi10Mg合金中的位错密度大幅增加,当变形量增加到68%时,AlSi10Mg合金α-Al晶粒被剧烈细化,合金的硬度被提高至116 HV,其强度可超过400 MPa,合金中的局部硬化区域导致其塑性变形能力下降,延伸率逐渐降低至25%。
Objective In recent years,laser additive manufacturing based on direct laser deposition has attracted widespread attention because of its flexibility and efficiency.This technology has a wide range of applications and high additive manufacturing efficiency.It is widely used in the aerospace,rail transit,and ship component maintenance equipment fields.However,high-strength aluminum alloys such as those in the Al-Zn-Mg-Cu series have a high content of alloying elements.During the solidification process,the semi-solid range of the alloy may exceed 100℃,which can easily leave gaps between aluminum grains.Theα-Al layer of liquid film generates cracks under the action of thermal stress,making laser deposition repair difficult.AlSi10Mg alloy,as a cast aluminum alloy,has the characteristics of a short semi-solid range and high strength,and is suitable for additive manufacturing and the laser repair of highstrength aluminum alloy components.However,during the laser deposition process,process fluctuations often cause defects such as pores to appear in the components,leading to cracks and ultimately component failure during use.Therefore,exploring a method to eliminate pores in components produced using AlSi10Mg laser deposition is of great significance for improving the mechanical properties and service life of AlSi10Mg components.Methods Atomized AlSi10Mg alloy powder with a particle size ranging from 53μm to 150μm is adopted.During the laser deposition process,the laser power is 2700 W,deposition speed is 600 mm/min,powder feed rate is 5.8 g/min,overlap amount is 2.5 mm,argon flow rate is 5 L/min,and protective argon amount is 20 L/min,resulting in a single-layer thickness of 0.5 mm.After depositing eight layers to achieve a thickness of 4 mm,stir friction treatment is performed on the deposited AlSi10Mg alloy.The height of the mixing needle of the mixing head is 4 mm,with a four-prism shape and diameter of 6 mm at the end of the prism.During the stirring friction treatment process,the rotational speed is 800 r/min,
作者
赵海生
张峰
杜成超
任旭东
魏翔宇
高俊杰
Zhao Haisheng;Zhang Feng;Du Chengchao;Ren Xudong;Wei Xiangyu;Gao Junjie(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,Chin;HFYC(Zhenjiang)Additive Manufacturing Co.,Ltd.,Zhenjiang 212132,Jiangsu,China;School of Materials Science and Engineering,Jiangsu University,Zhenjiang 212013,Jiangsu,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第16期232-242,共11页
Chinese Journal of Lasers
基金
国家自然科学基金(52205369)
江苏省自然科学基金(BK20210756)
江苏省博士后基金(2021K035A)。
关键词
激光技术
搅拌摩擦辅助激光沉积
AlSi10Mg合金
固溶强化
位错强化
韧性
laser technique
friction stir processing-assisted laser deposition
AiSiloMg alloy
solid solution strengthening
dislocation strengthening
toughness
