Effect of Sn Content on Filler and Bonding Characteristics of Active Metal Brazed Cu/Al2O3 Joint

Abstract

This study examined the effects of the Sn content in a pure active metal filler Ag-Cu-Ti for the brazing of a Cu/ Al 2 O 3 joint. The optimal content of Sn to effectively wet alumina was 5 wt%. The microstructure of the brazed joint showed the presence of an Ag-rich matrix and a Cu-rich phase, and Cu-Ti intermetallic compounds were observed along the bonded interface. The intermetallic compounds (IMCs) in the filler are found to increase when the Sn content in the alloy approaches to 10 wt%. These results suggest an extremely significant bonding strength of Cu/Al 2 O 3 joint using the Ag-Cu-Ti+Sn filler. The shear strength of the brazed joint increased with Sn content up to 5 wt%, reaching a maximum at ≈15 MPa. In addition, the strength decreased when the Sn content was higher than 5 wt%.

Recent Advances in Active Metal Brazing of Ceramics and Process

“…The average compressive strengths of five samples were 1477 MPa, which means a favorable joint strength [7]. Additionally, the authors reported a maximum shear strength of 15 MPa for Cu/Al 2 O 3 joint when brazed with AgCuTiSn filler metal [8].…”

High-Entropy Alloys for Micro- and Nanojoining Applications

“…Filler type also affects the brazing operation. Researchers have also used nanotechnology to develop various brazing fillers, known as composite fillers [27][28][29][30][31]. These nanocomposite fillers refine the various IMCs present in the matrix and joint.…”

Brazeability, Microstructure, and Joint Characteristics of ZrO2/Ti-6Al-4V Brazed by Ag-Cu-Ti Filler Reinforced with Cerium Oxide Nanoparticles

“…It is always a practical challenge to bond these ceramic materials directly due to a wide difference in physicochemical and mechanical properties of ceramics and metals that imposes a great challenge in microjoining operations [2]. For this purpose, various popular brazing fillers are already developed where the most popular ones are eutectic Ag-Cu or Ag-Cu-Ti alloys as reported in the past [3,4]. However, with regard to complex geometry, the thickness of IMCs, and cost, each filler is unique and has limitations of its own [5].…”

“…In such case, the selection of a superior filler metal is required for high reliability of brazed ceramic joints. If we inspect previous literatures, we see two major issues that are needed to be minimized in ceramic brazing, such as wetting of the contact surfaces and the stress development caused by the mismatch in mechanical and thermal properties of two contact materials that depend on the deformation characteristics of the filler used [1][2][3][4][5].…”

“…ere are various studies in the past where researchers have used metal or nonmetallic additives to control the brazing performance. More recently, Shin and his coworkers have improved the wetting and brazing property of Al 2 O 3 /Cu joints with the addition of Sn in the Ag-Cu-Ti alloy during the brazing process [3]. Halbig [14,15,[19][20][21][22][23].…”