One of the greatest challenges in FSW high-temperature alloys is designing a tool with the proper geometry and material combination to prevent tool deformation and wear.  EWI has designed a non-conventional tool referred to as a variable penetration tool (VPT).  The VPT geometry was combined with a low cost tungsten-based alloy.  The result is robust process for FSW Ti-64 providing a full penetration, defect free weld, with very little tool wear.

The initial process development successes lead to the application of this technology to butt, corner, and T-joint geometries.  These joint geometries were joined in lengths exceeding 60-in and in a variety of material thicknesses including .188-, .250-, and .500-in. 

Hybrid laser welding (HLW) is a process that combines laser welding and gas metal arc welding (GMAW).  This process combines the robustness of the GMAW with the penetration of lasers to create a process that can achieve deep penetration at high travel speeds with reduced fit up requirements.  The HLW process was used to join material combinations similar to FSW trials.  HLW of Ti-64 structures is discussed and compared to FSW.

This work was completed under Army Contact # DAAD19-03-2-002 to investigate joining of complex structures using these new advanced processes combined with modular tooling for rapid prototyping.  The success of this program has demonstrated feasibility of building Ti components in production for aircraft structures using both FSW and HLW.

The development of Friction stir welding (FSW) has progressed rapidly since its inception.  The process has been applied to a variety of high-temperature alloys, including titanium, with increasing success.  In the current study, FSW was used to join Ti-64 structures in the butt, corner, and T-joint configurations combining varying thicknesses of material.

One of the greatest challenges in FSW high-temperature alloys is designing a tool with the proper geometry and material combination to prevent tool deformation and wear.  EWI has designed a non-conventional tool referred to as a variable penetration tool (VPT).  The VPT geometry was combined with a low cost tungsten-based alloy.  The result is robust process for FSW Ti-64 providing a full penetration, defect free weld, with very little tool wear.

The initial process development successes lead to the application of this technology to butt, corner, and T-joint geometries.  These joint geometries were joined in lengths exceeding 60-in and in a variety of material thicknesses including .188-, .250-, and .500-in. 

Hybrid laser welding (HLW) is a process that combines laser welding and gas metal arc welding (GMAW).  This process combines the robustness of the GMAW with the penetration of lasers to create a process that can achieve deep penetration at high travel speeds with reduced fit up requirements.  The HLW process was used to join material combinations similar to FSW trials.  HLW of Ti-64 structures is discussed and compared to FSW.

This work was completed under Army Contact # DAAD19-03-2-002 to investigate joining of complex structures using these new advanced processes combined with modular tooling for rapid prototyping.  The success of this program has demonstrated feasibility of building Ti components in production for aircraft structures using both FSW and HLW.