TLP به روش MA857 ارتباط بين ساختار و خواص مكانيكي اتصال ايجادشده در سوپرآلياژ

MICROSTRUCTURE PROPERTIES RELATIONSHIP IN TRANSIENT LIQUID PHASE DIFFUSION BONDS MADE IN MA 758 SUPERALLOY

Transient liquid phase diffusion bonding procedure (TLP) was used to join an ODS MA758 superalloy in two conditions, wrought fine grains, and recrystallised grains. An Ni-Cr-B-Si alloy was used as an interlayet. Bonding was carried out at 1100°C for bonding hold times of 15,30, and 60 minutes under vaccume of 6 x 10-4 torr. Bonded samples were homogenized at 1360°C for one hour and then cooled with a rate of 15° C/min. Shear and fatigue strengths of bonds were determined. The results showed that there is no effect of bonding hold times on shear strength after bonding hold time of 30 minutes. At a given bonding hold time, the shear strength of bonds made in the recrystallized condition was greater than the shear strength of bonds made in the fine grain condition. The same was true for fatigue strength at a given cycle to fracture. TLP bonding was also carried out under pressure of 0.1 Mpa under the same temperature and bonding hold time for fine grain material. Microstructure studies of bonds made under pressure showed no effects of pressure on bond region grain size. Shear tests results also demonstrate little effects of pressure on shear strength of bonds.