Effect of minor au addition on glass-forming ability and mechanical properties of Pd-Cu-Au-Si-P alloys

Abstract

The glass-forming ability (GFA), thermal stability and mechanical properties of bulk glassy Pd79Cu6-xAuxSi 10P5 (x = 0-6 at%) alloys were studied. The results revealed that the minor substitution of Au for Cu strongly affects the thermal stability and GFA of Pd-Cu-Au-Si-P alloys. The alloy in which 2 at% Au was added to substitute Cu (Pd79Cu4Au2Si 10P5) exhibits the broadest supercooled liquid region (ΔTx = 80 K) and possesses the highest GFA among the alloys investigated. The critical diameter for glass formation of this alloy reaches ∼7 mm by copper mold casting. The GFA is dramatically reduced when the Au content is more than 5 at%, beyond which no bulk glasses could be formed. The Young's modulus, yield strength and maximum compressive strength of the best glass former (Pd79Cu4Au2Si10P 5) are 87 GPa, 1525 MPa and 1660 MPa, respectively, with & compressive plastic strain over 13%. © 2005 The Japan Institute of Metals.