Effects Of Alloying Elements On The Thermal Deformation Behaviors And Other Properties Of Ce-based Bulk Metallic Glasses

The bulk metallic glasses have progressively attracted considerable attention in the areas of materials and micro-molding due to its specific physical, chemical and mechanical properties. Especially, the Ce-based bulk metallic glasses have the merit of the room temperature supersplasticity, which makes it easily be processed into micro-parts. In this paper, the glass forming ability (GFA), thermal deformation behaviors and corrosion resistance of Ce-Cu-Al-Nb-M (M= Ga, Y, Co) bulk metallic glasses were studied.The GFA of Ce-Cu-Al-Nb-M (M= Ga, Y, Co) bulk metallic glasses was studied. It was found that with the increase of Ga content, the GFA of Ce69.5-xCu18Al11Nb1.5Gax(x= 0,1,2,3) alloy decreased, and showed a significant decrease with x=2. With the increase of Y content, the GFA of Ce69.5-xCu18Al11Nb] 5Yx (x=0,1,2,3) first increased then decreased, and showed best with x=2. With the increase of Y content, the GFA of Ce69.5Cu18-xAl11Nb1.5Cox (x=0,5,10,15) first increased then decreased, and showed best with x=5. Meanwhile, the thermodynamic criterion Trg and y were studied. It was found that y was effective in evaluating the GFA of Ce-based bulk metallic glasses.The compression performance of Ce-Cu-Al-Nb-M (M= Ga, Y, Co) bulk metallic glasses at 363 K and a strain rate of 1 × 10-3 s-1 was studied. The results indicated that the macroscopic plastic deformation ability of Ce69.5-xCu1gAl11Nb1.5Gax (x= 0,1,2,3) alloy worse while the amount of Ga increased. The strain of the alloy achieved predetermined with x=1 then decreased with x>1 but final brittle fracture with x=3. With the increase of Y content, the flow stress became lower and strain platform more extended with x=0-2 while showed small plastic strains and ruptured with x=3. With the increase of Co content, the flow stress of Ce69.5Cu18-xAl11Nb1.5Cox (x= 0,5,10,15) increased and the strain achieved predetermined with x=0 and 5. But the strain decreased with x>5 and exhibited the direct brittle fracture with x=15.The effects of different strain rate (1x10-1 s-1, 1×10-2 s-1, 1×10-3 s-1,5×10-4 s-1) and temperature (363 K,373 K,383 K,393 K) on Ce69.5Cu18Al11Nb1.5, Ce67.5Cu18Al11Nb1.5Y2and Ce69.5Cu13Al11Nb1.5Co5 were studied. It showed that with the decrease of strain rate and increase of temperature, the flow stress decreased. The alloys became easily brittle fracture at lower temperature (363 K) and a higher strain rate (1×10-1 s-1). Meanwhile, the strain rate had greater effects on the strain of Ce-based bulk metallic glasses than the temperature.The corrosion resistance of Ce-Cu-Al-Nb-M (M= Ga, Y, Co) at 0.3M NaCl and room temperature was studied. The results indicated that with the increase of Ga content, the corrosion resistance of Ce69.5-xCu18Al11Nb1.5Gax (x= 0,1,2,3) alloy decreases. With the increase of Y content, the corrosion resistance of Ce69.5-xCu18Al11Nb1.5Yx (x=0,1,2,3) first increased then decreased, and showed best with x=2. The corrosion resistance of Ce69.5Cu18-xAl11Nb1.5Cox (x=0, 5,10,15) also first increased then decreased while the amount of Y increased, and showed best with x=5.