Original Article

Effect of laser-to-wire distance on the stability of laser-arc hybrid welding for mold steel

College of Mechanical and Vehicular Engineering, Changchun University, Changchun 130022, PR China

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Received: 31 March 2025
Accepted: 30 June 2026

Abstract

In laser‒arc hybrid welding for mold manufacturing, process stability is critically affected by the laser‒to‒wire distance. This study aims to clarify how this distance influences welding stability in S136 mold steel. An integrated analysis of weld bead geometry, droplet transfer behavior, keyhole dynamics, and voltage/current signals was performed. Results show that increasing the laser‒to‒wire distance widens the weld bead but reduces the penetration depth, while keyhole stability progressively deteriorates. The droplet transfer mode transitions from stable spray to globular and finally to unstable projected transfer, reflecting increasing process instability. This behavior is attributed to the weakening laser‒arc interaction, which reduces the plasma drag force and the electromagnetic constriction force acting on droplets. Among the distances tested, the best stability is achieved at 3 mm. These findings provide mechanistic insight into how laser‒to‒wire distance governs process stability and offer a basis for selecting a robust process window.