摘要
金属粉末冷喷涂(Cold Spray)作为一种新型固态增材制造技术,由于其快速的沉积过程和适用于金属材料大规模制造的特点而受到学术界和工业界的广泛关注.冷喷涂过程涉及粉末颗粒高速冲击、材料大变形、相变和射流等复杂现象,难以精确模拟.其涉及多颗粒制造的内在机理尚不明确.本文基于改进的光滑粒子动力学法(Smoothed Particle Hydrodynamics,SPH),实现了对于多层斜冲击金属冷喷制造的有效模拟.研究了单颗粒斜冲击下的颗粒变形及与基板结合特征,进一步模拟分析了斜冲击下多层多颗粒冷喷制造问题.模拟研究发现,斜冲击下多层颗粒与基板的结合情况与正冲击有很大区别,更容易出现颗粒间的脱离以及颗粒与基板间的空腔现象.同时本文实现了随喷嘴运动的冷喷涂全过程模拟,获得了喷涂通道在不同角度冲击下的几何特征,对于颗粒增材制造技术的发展与改进具有重要意义.
As a novel solid-state additive manufacturing technique,metal powder cold spray(CS)can rapidly deposit materials and be suitable for large-scale manufacturing of metal structures.Hence,the CS technique has attracted considerable interest in engineering and science.CS involves several complex processes,such as high-velocity impacting of metal powders,large material deformations,phase change,and jetting,which are difficult to simulate accurately.This work employs an improved smoothed particle hydrodynamics(SPH)method to effectively model multilayer CS with oblique impacting powders.The deformation characteristics and bonding effects between powders and a substrate are numerically investigated.Moreover,the multilayer CS processes with multiple impacting powders are analyzed.Results showed that the bonding effects between powders and a substrate under oblique impacting conditions have several differences from that under normal impacting conditions.The separation between powders and cavities can be observed in oblique impacting CS.Furthermore,the entire CS process with the movement of the nozzle has been reproduced by the present SPH method.The geometric characteristics of the powder track in CS with different impacting angles have also been analyzed,which can help develop and improve additive manufacturing techniques.
作者
张智琅
舒昌
刘阳阳
李桥忠
刘蔚
ZHANG ZhiLang;SHU Chang;LIU YangYang;LI QiaoZhong;LIU Wei(Department of Mechanical Engineering,National University of Singapore,Singapore 119260,Singapore;College of Aerospace Engineering.Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)
出处
《中国科学：物理学、力学、天文学》
CSCD
北大核心
2022年第10期74-86,共13页
Scientia Sinica Physica,Mechanica & Astronomica
基金
新加坡教育部一级项目(编号:R-265-000-685-114)资助。
关键词
冷喷涂
增材制造
光滑粒子动力学法
多层颗粒
斜冲击
cold spray
additive manufacturing
smoothed particle hydrodynamics
multi-layer powders
oblique impacting
