Formation of bulk Pt–Pd–Ni–P glassy alloys

The thermal behavior of (Pt0.4Pd0.3Ni0.3)100−xPx (x = 16–25 at.%) glassy alloys has been investigated. It is found that the crystallization behavior of the (Pt0.4Pd0.3Ni0.3)100−xPx glassy alloys changes from a single-stage exothermic reaction to a two-stage exothermic reaction depending on phosphorous content. When the phosphorous content is 23 at.%, the glassy alloy exhibits the largest supercooled liquid region (ΔTx) and a sharp single exothermic peak. Fixing the phosphorous content at 23 at.%, the Pt77−x−yPdxNiyP23 (x = 7.7–61.6 at.%, y = 7.7–61.6 at.%) glassy alloys have a wide composition range in which the glassy alloys exhibit a large supercooled liquid region (ΔTx beyond 60 K). In this range, the Pt30.8Pd23.1Ni23.1P23 glass has the largest ΔTx (77 K) and a high reduced glass transition temperature (Trg) of 0.60. This alloy can be cast into fully glassy rods with a diameter of 3 mm. Under uni-axial compression, bulk Pt30.8Pd23.1Ni23.1P23 glassy alloy has an elastic strain of ∼2%, an ultimate strain (to fracture) of ∼6.4%, a Young’s modulus of ∼106 GPa and a failure strength of ∼1390 MPa.