New Solution for High-Efficiency Welding of Medium-Thick Titanium Alloy Plates

01 Introduction

Medium-thick titanium alloys, due to their excellent specific strength, corrosion resistance, and high-temperature performance, have broad application prospects in high-end fields such as aerospace, marine engineering, and chemical equipment. However, their welding formation faces great challenges: traditional welding methods (LBW, TIG, MIG) involve high heat input and slow cooling rates, which easily lead to coarse grains at the joints, severe deformation, and low production efficiency, making it difficult to meet the requirements for high-quality and efficient manufacturing. To overcome this bottleneck, laser-arc hybrid welding technology emerged, which leverages the synergistic energy advantages of both laser and arc. This significantly improves penetration depth, welding speed, and process stability, while also enhancing weld formation quality. This paper focuses on four types of high-efficiency hybrid welding processes: laser-MIG hybrid welding, laser-TIG hybrid welding, laser-CMT hybrid welding, and plasma-MIG hybrid welding, analyzing their technical characteristics and potential applications in medium-thick titanium alloy welding.

02 Characteristics of Different Laser-Arc Hybrid Welding Methods for Titanium Alloys

Compared with LBW, laser-MIG hybrid welding demonstrates its unique “1+1>2” synergistic effect in addressing the welding challenges of medium-thick titanium alloys. Its core advantage comes from the complementary physical characteristics of the two heat sources: the high energy density of the laser produces a deep and narrow molten pool, providing sufficient penetration and ensuring a high welding speed; while the MIG arc can preheat the welding area, stabilize the laser plasma, and significantly increase deposition rate through wire melting.

Laser-TIG hybrid welding technology, by ingeniously integrating the high energy density of the laser with the excellent stability of the TIG arc, shows remarkable comprehensive advantages in welding medium-thick titanium alloys. The laser is responsible for deep-penetration welding, ensuring a large depth-to-width ratio of the weld, while the TIG arc not only broadens process adaptability and increases tolerance to assembly gaps but also reduces porosity and cracking tendency through pre-melting and slow cooling. This process is particularly suitable for titanium alloys that are sensitive to oxidation and have special thermophysical properties. The inert gas protection effect of the TIG arc further suppresses high-temperature oxidation in the weld zone, improving joint quality. At present, this technology has been applied to critical titanium alloy components in aerospace engine parts and ship pressure-resistant structures. Research focuses on multi-heat source parameter synergy control, weld formation optimization, and process monitoring, to achieve high-quality, low-deformation, and efficient welding of medium-thick titanium alloys.

Laser-TIG Hybrid Welding: Mechanism and Characteristics for Thick Ti Alloy

Laser-CMT hybrid welding technology is an innovative laser-arc hybrid welding method that combines the high energy density of the laser with CMT technology. Compared with traditional laser-MIG hybrid welding, this technology shows significant advantages in welding medium-thick titanium alloys: its ultra-low heat input can effectively suppress coarsening and deformation in the heat-affected zone, while its spatter-free and stable droplet transfer greatly enhances weld formation quality. At the same time, the precise control of arc length in the CMT process, combined with the stabilizing effect of the laser keyhole, further reduces porosity and lack of fusion defects, significantly improving the consistency and reliability of welded joints. It provides an advanced process solution for the manufacturing of medium-thick titanium alloy structures with high precision and quality requirements.

Plasma-MIG hybrid welding technology is a new type of hybrid heat source welding method that effectively combines plasma arc welding and MIG welding. The plasma arc has high energy density and strong penetration capability, while MIG welding provides higher filling efficiency. Combining the advantages of both processes in terms of greater penetration depth and high melting efficiency, this technology can improve the welding efficiency of medium-thick plates.

03 Summary

Laser-MIG hybrid welding is the most widely used method for joining medium-thick plates. Compared with LBW and MIG, laser-MIG hybrid welding has superior gap adaptability and higher penetration, enabling efficient welding of titanium alloy plates. Laser-TIG hybrid welding can achieve single-sided welding and produce titanium alloys with specific requirements, thereby reducing porosity problems associated with single-pass laser welding and lowering assembly precision requirements. It is especially suitable for large blunt-edge welding in medium-thick titanium alloy applications. In addition, although advanced welding technologies such as laser-CMT hybrid welding and plasma-MIG hybrid welding have shown unique potential in medium-thick titanium alloy welding with low heat input and high precision, research on these methods is still limited. With continuous technological progress, the former is expected to become an efficient solution for high-precision structures, while the latter has irreplaceable application prospects in single-pass welding of large-thickness components.

**--Cite the article published by 高能束加工技术 on August 29, 2025, in the WeChat public account "High-Energy Beam Processing Technology and Applications."