In the welding process of titanium alloy tubes in the factory, the depth of the weld is determined by the thickness of the titanium tube.
Therefore, the production objective is to improve formability by reducing weld width and achieving higher speeds simultaneously. When selecting the most suitable laser, you cannot only consider the quality of the beam, but also the precision of the tube rolling mill.
Furthermore, before the dimensional inaccuracies of the laminating machine come into play, one must first consider the constraints encountered when reducing the beam spot size.
There are many size-related problems in welding titanium tubes, but the main factor that affects the welding process is the seam in the welding box.
Once the titanium plate is ready for welding after forming, the characteristics of the weld seam include: gaps between the titanium plates, severe or small welding misalignment, and changes in the seam centerline. The gap determines the amount of material needed to form the weld pool.
Excessive pressure may lead to excess material on the top or inner diameter of the titanium alloy welded tube. On the other hand, severe or minor misalignment of the weldment can result in a poor appearance of the weldment.
In both scenarios, the titanium plate is cut and cleaned, rolled and then taken to the welding point. Additionally, a refrigerant is used to cool the induction coil used during the heating process.
Finally, some refrigerant will be used in the extrusion process. Here, a large force is applied to the extrusion roller to avoid porosity in the welding area; however, the use of greater extrusion force can lead to an increase in burrs (or weld beads). Therefore, specially designed tools are used to remove burrs from inside and outside the pipe.
One of the main advantages of the high frequency welding process is its ability to process titanium tubes at high speeds. However, a typical situation in most solid-phase forgings is that high-frequency spot welding is not easily tested reliably using conventional non-destructive techniques.
Welding cracks can appear in the thin flat areas of low-strength joints that traditional methods cannot detect, potentially compromising reliability in some high-demand automotive applications.
Traditionally, titanium tube manufacturers opt for gas tungsten arc welding (GTAW) to complete the welding process. GTAW generates an electric welding arc between two non-consumable tungsten electrodes.
At the same time, an inert shielding gas is introduced into the torch to protect the electrodes, create ionized plasma flow, and protect the molten weld pool.
This is an established and well-understood process that consistently delivers high-quality welding results. Therefore, the success of the titanium alloy tube welding process depends on the integration of all individual techniques, requiring their treatment as a comprehensive system.
In all titanium tube welding applications, the edges of the titanium sheet are melted, and by clamping the edges of the titanium tube using a clamping bracket, solidification occurs. However, laser welding is characterized by high-energy beam density.
The laser beam not only melts the surface of the material, but also creates a keyhole, resulting in a narrow weld profile. To weld titanium alloy tubes, a flat sheet of titanium is first formed and subsequently shaped into a cylindrical tube.
Once formed, the seams of the titanium alloy tube must be welded. This seam significantly influences the formability of the part. Therefore, choosing the appropriate welding technique is crucial to obtaining a weld profile that can meet the stringent testing requirements of the manufacturing industry.
Undoubtedly, gas tungsten arc welding (GTAW), high frequency (HF) welding and laser welding have found their applications in the manufacture of titanium alloy tubes.
