Effect of Sn addition on the glass-forming ability and mechanical properties of Ni-Nb-Zr bulk metallic glasses

• 来源期刊: 科学通报(英文版)
• 学科: 工学
• 年，卷（期）: 2011,（36）
• 页码范围: 3926-3931
• 页数: 6页
• 分类号: TG139.8
• 语种: 中文

摘要

The effect of tin (Sn) addition on the glass forming ability (GFA) and mechanical properties of the Ni-Nb-Zr ternary alloy system has been studied. The addition of Sn improves the GFA; Ni61Nb35.5-xZr3.5Snx (in at.%) alloys with x=1 can be cast into amorphous samples at least 3 mm in diameter using a copper mold injection-casting method. The critical size for glass formation decreases to 2 mm when x=5 because Ni2SnZr phase precipitates readily. The addition of Sn is also effective in enhancing the stability of the supercooled liquid; a maximum supercooled liquid region of 48 K was attained for the Ni61Nb30.5Zr3.5Sn5 alloy. Compression tests reveal that the Ni61Nb33.5Zr3.5Sn2 alloy possesses the best mechanical properties,with yield strength~3180 MPa,fracture strength~3390 MPa and plastic strain ~1.3%. The fracture surfaces examined by scanning electron microscopy indicate that the alloys have a transition from ductility to brittleness in fracture behavior. The combination of high GFA,high thermal stability,high strength and compressive plasticity makes these alloys potentially attractive for engineering applications.