Abstract
In order to decrease the completion time during TLP-bonding, an iron-based filler metal, (IM-7) comprising MA956 base metal containing 7 mass%Si and 1 mass%B was developed to join MA956 base material. TLP-bonded joints free of microvoids and bondine intermetallic phases were obtained using a bonding temperature of 1563 K, a holding time of 2.16 ks and an applied pressure of 7.0 MPa. The bondline region in TLP-bonded MA956 base metal had a bamboo-like microstructure. In order to make clear the formation mechanism of this microstructure, the growth mechanism of solid phase during isothermal solidification was evaluated. During tensile testing at 923 K, the joints TLP-bonded at 1563 K-for 2.16 ks fractured in the base metal zone and consequently, the mechanical properties of the joint region and the base metal were similar. The creep rupture properties of the joint regions were close to the base metal properties in the transverse direction.
