Bonding Al₂O₃ to SUS304 by Pulse Current Heated Bonding after Brazing Ag, Cu Thin Plate to Al₂O₃, SUS304

Abstract

Crack propagates in Al₂O₃ when Al₂O₃ is bonded to SUS304 by Ag-Cu-Ti brazing. This crack is due to residual stress in Al₂O₃. Bonding Al₂O₃ to SUS304 by pulse current heated bonding after brazing Ag, Cu thin plate to Al₂O₃, SUS304 was studied for the purpose of prevention of this crack. Effect of residual stress relief was evaluated with thermo-elasto-plastic analysis by FEM and joint properties were investigated by bonding test. Main results obtained are as follows :
(1) It was confirmed with FEM that residual stress in Al₂O₃ could be reduced by proposed bonding method. Insert of soft metal (Ag, Cu) and thermal load reduction by pulse current heated bonding are effective for residual stress relief in Al₂O₃.
(2) Crack in Al₂O₃ doesn't generate and excellent joint strength is obtained by proposed bonding method. Joint strength obtained by optimum bonding parameters is 119-122 MPa (average value) at 4 point bending test.