超声波辅助激光熔化沉积Al-12Si合金致密化工艺研究  

Densification Process of Al-12Si Alloys Prepared by Ultrasonic-Assisted Laser Metal Deposition

作　　者：陈研 张洋 郭玉奇 齐海波 Chen Yan;Zhang Yang;Guo Yuqi;Qi Haibo(School of Materials Science and Engineering,Shijiazhuang Tiedao University,Shijiazhuang,Hebei 050043,China)

机构地区：[1]石家庄铁道大学材料科学与工程学院,河北石家庄050043

出　　处：《应用激光》2021年第1期51-58,共8页Applied Laser

基　　金：国家自然科学基金青年基金项目(51705344);国家自然科学基金面上项目(51775359)。

摘　　要：采用超声波辅助激光熔化沉积法制备了Al-12Si试样,研究了激光功率、扫描速度、扫描间距及超声波功率对沉积层致密度的影响规律,采用金相显微镜、扫描电镜、电子背散射衍射技术和拉伸试验分析了工艺优化后沉积试样的微观组织和力学性能。结果表明,沉积试样的致密度随着激光功率、超声波功率的增大而增大,随着扫描速度、扫描间距的增加先增加后降低。当采用激光功率1 100 W、扫描速度6 mm/s、扫描间距1.0 mm、超声波功率1 000 W的工艺参数,对同一沉积层进行两次相互垂直的扫描策略时,能够获得沉积层致密度最高为99.1%的试样。此时沉积层中主要由晶粒尺寸为2.5~75μm的α-Al固溶体和铝硅共晶两种组织构成。由于试件致密度的提高,其抗拉强度和延伸率分别比无超声波下最优工艺试件提高了17%和53%。In this study, the Al-12 Si alloys were prepared by the ultrasonic-assisted laser metal deposition method. The effect of laser power, scanning speed, scanning spacing and ultrasonic power on the density of the deposited layer was investigated. The microstructure and mechanical properties were analyzed using metallographic microscope, scanning electron microscope, electron backscatter diffraction technology and tensile test. The results show that the density of deposited samples increases with the enhance of laser power and ultrasonic power, and first improves and then reduces with the increase of scanning speed and scanning spacing. When the process parameters of laser power 1 100 W, scanning speed 6 mm/s, scanning spacing 1.0 mm, and ultrasonic power 1 000 W were used, and the same deposition layer was scanned twice perpendicular to each other, the sample with the highest density of 99.1% could be obtained. At this time, the deposited layer was mainly composed of α-Al solid solution with grain size of 2.5~75 μm and Al-Si eutectic. Due to the improvement of the density, the tensile strength and elongation of the ultrasonic optimal test specimen were 17% and 53% higher than those of the optimal test specimen without ultrasonic vibration.

关 键 词：激光熔化沉积 Al-12Si合金 超声振动 致密度 

分 类 号：TN249[电子电信—物理电子学]