The first stage of experiments demonstrated stable good results on a short-time strength and ductility of BJ, made using a composite brazing alloy
#1 + 20% NS12 + 60% Rene-142 (Table 1).
In case of repair brazing of the components from cast nickel heat-resistant alloys (HA) the same methods of treatment are used for renovation of the brazed joints (BJ), which include high-temperature annealing for equalization of chemical gradients, ensuring of full diffusion interaction between the solidified melt of the brazing alloy
and walls of the item being brazed, and achievement of necessary mechanical characteristics of the seam metal and BJ in the process of operation .
Resistance to coagulation and dissolution of [gamma]'-phase in brazing of HTA are determined by alloying complex of the seam metal, in connection with which chemical composition of the low-temperature brazing alloy
and the filler are factors, which determine level of the compound heat stability.
For optimization of properties of brazed joints amount of boron in the brazing alloy
material should completely ensure saturation of the alloy boundaries of a component being renovated, whereby formation of boride phases directly in the brazed seam metal should not be allowed.
Mg content in the filler and the brazing conditions must be taken together into consideration when designing the brazing alloy
, for example, Al-4Mg-0.5Si-0.4Mn alloy showed a good result of 117 MPa in torch brazing but produced only 61 MPa in vacuum brazing .
This filler metal is termed as brazing alloy
or braze alloy.
is metalized on a ceramic surface, and nickel (Ni) plating is applied, then brazing alloy
(BAg-8) is used for joining.
Thanks to the neutral flame and high temperature (3650 deg C) the brazing alloy
penetrates deeper into the joint producing stronger connections.