Linear Friction Welding of a Single Crystal Superalloy

Abstract

The effect of forging pressure on linear friction welding (LFW) behaviour of a single crystal Ni-based superalloy was investigated. Crystal orientations of the specimens were controlled and results indicated that welding success is dependent on proximity of the oscillation direction to the <011> direction. Characterization of the welds included optical examination of the microstructural features of the weld and thermomechanically affected zones (TMAZ) in relation to the parent material. Mechanical properties of the welded material examined via microhardness testing showed an increase in strength in the weld zone (WZ). Microstructural examination indicated that some recrystallization occurred in the WZ, as well as a small amount of distortion of the dendrites in the TMAZ. With increased forge pressure, recrystallized grains remaining in the weld were minimized.

Maximizing the integrity of linear friction welded Waspaloy

“…To date, little work has been published on the integrity (tensile properties) of LFWed Ni-base superalloys, although detailed microhardness, microstructure (grain size and particles evolution) and residual stress analyses across the weld have been reported for IFWed and LFWed Ni-base superalloys such as Inconel-718 [11][12][13], Udimet-720LI [12,[14][15][16], RR ® 1000 [12,17], Inconel-738 [18], Waspaloy [5,19] and Ni-base single crystals [20]. Limited data published by Li et al [21] on dissimilar LFW of Udimet-720LI to Inconel-718, indicated that, the total elongation and yield strength of the weldment were respectively 12% and 110% that of the weaker parent material (i.e.…”

Microstructure evolution in a single crystal nickel-based superalloy joint by linear friction welding

“…Ola et al [17] studied the LFW of single crystal CMSX-486 superalloy, to find that the compressive load during forging induced rapid solidification of the metastable liquid phase which led to appearance of the Hf-based oxide phase along the weld. Wanjara et al [18] found that forging pressure also had an important influence on LFW of a single crystal superalloy. With increasing forging pressure, the remaining recrystallised grains in the weld were minimised and the size of the WZ, TMAZ decreased.…”

Analysis of Microstructure Evolution and Mechanical Properties of Linear Friction Welded Titanium Alloys

“…Studies of LFW have been conducted on a wider range of materials. For example, studies conducted on the Ni-based superalloys show that optimized process parameters and controlled crystal orientations can produce well-integrated welds [11][12]. In addition, intermetallics such as nickel aluminides [13] and gamma titanium aluminides [14][15] have been successfully welded using the LFW technique.…”