1996 Volume 14 Issue 3 Pages 516-522
We have demonstrated that the application of ultrasonic vibration changes the tensile strength of austenitic stainless steel joints brazed with Ag-based filler metal. In this paper, we employed six kinds of filler metals which were prepared in a laboratory and studied the relation between the tensile strength of the joints and the microstructure of the brazed layer in order to obtain more understanding in terms of the factors and mechanisms governing the increase in the tensile strength of the joints.
It seems that the factors which increase the tensile strength of the brazed joints with applying ultrasonic vibration are : 1. Achievement of grain refinement in brazed layer ; 2. Acceleration of the dissolution of base metal into filler metal followed by solid-solution hardening of brazed layer through the dissolved elements ; 3. Tensile strength increase due to the shift of the brazed layer composition to eutectic one at which eutectic alloys show the highest tensile strength ; 4. Solid-solution strength-ening of brazed layer resulting from the increase in crystallization of solid solution composed of main elements in filler metal.