Wetting and Mechanical Performance of Zirconia Brazed with Silver/Copper Oxide and Silver/Vanadium Oxide Alloys

Abstract

The wetting behavior and mechanical strength of silver/copper oxide and silver/vanadium oxide braze alloys were investigated for both magnesia‐stabilized and yttria‐stabilized (Mg‐PSZ and Y‐TZP) transformation toughened zirconia substrates. The temperatures investigated were 1000–1100 °C, with oxide additions of 1–10 wt% V2O5 or CuO, and hold times of 0.9–3.6 ks. Increasing either the isothermal hold temperature or time had a distinctly negative effect on the joint strength. The maximum strengths for both braze alloys were obtained for 5 wt% oxide additions at 1050 °C with a hold time of 0.9 ks. The Mg‐PSZ/Ag‐CuO system exhibited a average fracture strength of 255 MPa (45% of the reported monolithic strength), and the Y‐TZP/Ag‐CuO system had an average fracture strength of 540 MPa (35% of the reported monolithic strength). The fracture strengths were lower for the Ag‐V2O5 braze alloys, with fracture strengths of approximately 180 MPa (30% of the monolithic strength) for Mg‐PSZ versus approximately 160 MPa (10% of the monolithic strength) for Y‐TZP. The fracture always occurred at the braze–ceramic interface. No interfacial products were observed in low magnification SEM analysis for the brazing alloys containing V2O5 additions, while there were interfacial products present for brazes prepared with CuO additions in the braze alloy.

Wetting Behavior of the Ag-5CuO Brazing Alloy on ZTA Composite Ceramic with/without CuO Coating in Air

“…This revealed that the addition of 5 wt.% CuO into pure Ag can significantly promote the wettability of pure Ag on ZTA ceramic in air. Similar effects of CuO on the wettability of Ag on Al2O3 and YSZ have been reported in previous studies [23,24]. Secondly, the contact angle in the pure Ag/ZTA/N2 wetting system was about 60° higher than that in the pure Ag/ZTA/air wetting system, confirming that oxygen played an important role in reducing the contact angle of pure Ag on ZTA ceramic.…”

Study on Reactive Air Brazing of p-SiO2 Ceramic with Ag-xCuO Filler Metal

“…Glass was one of the main filler metals used in RAB, but due to its poor fluidity and high brittleness, pores and cracks easily formed in the joint. Another filler metal was composed of noble metals (Ag, Au, Ag-Pt [20]) and metal oxides (Al 2 O 3 , CuO [21], V 2 O 5 [22]). Compared to the above filler metal systems, Ag-CuO was less expensive and could provide better wettability and toughness.…”