THERMODYNAMIC MODELING AND EXPERIMENTAL INVESTIGATION OF BRAZED JOINTS USED IN AEROSPACE INDUSTRY

The kinetics of isothermal solidification during the TLPbrazing of nickel superalloys, Inconel 625 and 718, and stainless steel, SS 410, with BNi-2 filler alloy has been studied through a combination of modeling and experimental investigations. It was observed that the boron diffusion model and migrating solid/liquid interface model predicted the isothermal solidification times relatively accurately when nickel superalloys were used as base metals; however, silicon diffusion model was more accurate for stainless steel base metal due to the increased solubility of boron in the multicomponent melt. A revision of boron diffusion model parameters was given for the SS 410/BNi-2 combination for better approximation of holding time and to calculate the composition of the residual liquid when the holding time was not long enough to complete the isothermal solidification.

[1]  O. Ojo,et al.  Isothermal solidification during transient liquid phase bonding of Inconel 738 superalloy , 2004 .

[2]  O. Ojo,et al.  Effect of gap size and process parameters on diffusion brazing of Inconel 738 , 2004 .

[3]  H. Shih,et al.  Evolution of microstructure of AISI 304 stainless steel joint brazed by mechanically alloyed nickel base filler with different silicon content , 2003 .

[4]  R. Shiue,et al.  Infrared repair brazing of 403 stainless steel with a nickel-based braze alloy , 2002 .

[5]  Weixing Chen,et al.  Effect of boron segregation at grain boundaries on heat-affected zone cracking in wrought INCONEL 718 , 2001 .

[6]  T. Narita,et al.  Isothermal Solidification Behavior During the Transient Liquid Phase Bonding Process of Nickel Using Binary Filler Metals , 2001 .

[7]  W. Boettinger,et al.  Transient liquid-phase bonding in the Ni-Al-B system , 2000 .

[8]  B. Zorc,et al.  Comparación de uniones soldadas hechas con aleaciones de níquel BNi-1 y BNi-7 , 2000 .

[9]  T. Narita,et al.  Numerical modeling of the transient liquid phase bonding process of Ni using Ni-B-Cr ternary filler metal , 1999 .

[10]  S. K. Tung,et al.  Solidification phenomena in nickel base brazes containing boron and silicon , 1996 .

[11]  Stephen Liu,et al.  Diffusion brazing in the nickel-boron system , 1992 .

[12]  W. Gale,et al.  Microstructural development in transient liquid-phase bonding , 1991 .

[13]  T. B. Massalski,et al.  A study of the transient liquid phase bonding process applied to a Ag/Cu/Ag sandwich joint , 1988 .

[14]  E. Lugscheider.  High Temperature Brazing of Stainless Steel with Nickel-Base Filler Metals BNi-2, BNi-5 and BNi-7 Best results in Type 316 stainless steel butt joints are obtained when brazing with BNi-2 and BNi-5 filler metals is followed by heat treatment , 1983 .

[15]  Paul Shewmon,et al.  Diffusion in Solids , 2016 .

[16]  John Crank,et al.  The Mathematics Of Diffusion , 1956 .