Solid-phase weldability of sheets titanium alloy VT6 at low temperature

The solid-phase weldability of industrial two-phase titanium alloy VT6 in the temperature range T=750. 900 degrees C is experimentally studied. Metallography researches showed that during (t=2 hours) solid-phase joining at the temperature T=900 degrees C the mean grain size of a-phase had grown up to d=6,0+/-1 mu m. With decreasing a welding temperature down to T=750 degrees C, the mean size of a -grains does not change significantly, as compared to initial. The quality of solid-phase joint (SSJ) investigated by mechanical tensile and shear tests. The results of mechanical tests specimens showed, that after welding at the temperature of T=900 degrees C the shear strength is 83 %, and with a decreased in a welding temperature to T=750 degrees C, specimens saved strength properties, and shear strength of SSB is equal to 96 % from corresponding strength of basic material. The presence of pores in the zone of SSJ of VT6 alloy does not have influence on his strength properties, which is comparable with strength of basic material. Fractography research of surface of SSJ of the destroyed specimens after tests on a change showed that united at the elevated temperature of T=900 degrees C destruction take place in the zone of viscous destruction. With decreasing welding temperature down to T=750 degrees C, specimens destruction take place in the zone of fragile-viscid destruction. The analysis of the results mechanical tests has shown that mechanical behavior considerably depends on the welding temperature. As the pressure welding temperature is decreased from T=900 degrees C down to 750 degrees C the shear strength level of both the base material and the SSJ material is conservation.