Characteristics analysis of droplet transfer in laser-MAG hybrid welding process

•The motion characteristics of droplets in hybrid arc space are described.•The action of metal vapor ejected from laser keyhole on droplet is analyzed.•The laser plasma compresses the arc and leads to the increase of the electromagnetic resistance of the droplet transfer. The droplet transfer, plasm...

Full description

Saved in:
Bibliographic Details
Published in:International journal of heat and mass transfer 2018-06, Vol.121, p.805-811
Main Authors: Liu, Shuangyu, Zhang, Fulong, Dong, Shengnan, Zhang, Hong, Liu, Fengde
Format: Article
Language:English
Subjects:
Acceleration
Coalescing
Droplets
Force distribution
High nitrogen steel
High speed cameras
Image processing
Laser beam welding
Laser-arc hybrid welding
Mathematical analysis
Mathematical morphology
Mechanics analysis
Metal droplet
Metal vapors
Morphology
Nitrogen
Plasma arc welding
Recoil
Stress concentration
Welding
Welding current
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:•The motion characteristics of droplets in hybrid arc space are described.•The action of metal vapor ejected from laser keyhole on droplet is analyzed.•The laser plasma compresses the arc and leads to the increase of the electromagnetic resistance of the droplet transfer. The droplet transfer, plasma morphology and droplet morphology of laser arc hybrid welding process are collected and analyzed using high speed camera. The force magnitude and acceleration of motion droplets in the arc space are calculated by the image processing and mathematical calculations. The value and distribution of the recoil force from the metal vapor on droplets are calculated. The results show that the globular transfer mode corresponds to the welding current is approximate 180 A; the streaming transfer mode corresponds to the welding current is approximate 200 A. The laser has a compress effect on the arc, and the compression on the surface of the weld pool is stronger. The acceleration of the droplet detachment from wire is 70 m/s2 and 50 m/s2 for arc welding and laser arc hybrid welding separately. In the actual welding process, the reaction force of metal vapor on molten droplets is very small, when the distance between droplet and keyhole in the surface of the weld pool is 3 mm. The pressure difference on the surface between upper and lower of the droplet is great, which results the droplet coalescence and the transfer frequency slows down.
ISSN:0017-9310
1879-2189
DOI:10.1016/j.ijheatmasstransfer.2018.01.047