At present, FeMn-based degradable alloys prepared by direct sintering generally face the problems of Mn volatilization, difficult densification, and poor mechanical properties. In this work, a Fe-35Mn-0.5C alloy with low Mn volatility, high density, and favorable mechanical properties is fabricated by the metal injection molding (MIM) process. The effects of sintering pressure and minor carbon addition on microstructure and mechanical properties were studied. The corresponding mechanical deformation mechanism was discussed. The results show that a significant reduction in the proportion of Mn volatilization to less than 0.5% and higher relative density of 97 ± 0.30% are achieved in the MIM-treated Fe-35Mn-0.5C alloy by pressurized sintering at 5 atm and 0.5 wt.% carbon addition. The optimized tensile properties are attained, with an ultimate tensile strength of 772 MPa, yield strength of 290 MPa, and elongation of 35% at room temperature, which meets the mechanical needs of metallic materials for biologically implantable medical devices.
17 July 2014 in Advances in Materials Science and Engineering
The effect of Al addition on mechanical properties and plastic deformation behavior of (Ti45Cu40Zr10Ni5)100−xAlx(x= 0, 2, 4, 6 and 8) amorphous alloy ribbons have been investigated by nanoindentation. The hardness and elastic modulus do not simply increase with the increase of Al content. The alloy with 8 at.% Al exhibits the highest hardness and elastic modulus. The serrations or pop-in events are strongly dependent on the loading rate and alloy composition.
Structural and thermal properties of binary () alloys obtained by melt spinning and copper mold casting methods were investigated. The fully amorphous samples in a bulk form cannot be obtained in the binary Ni-Zr alloys over a wide composition range, though they have and values close to or even higher than those of the binary Cu-Zr bulk metallic glasses (BMGs). The low thermal stability of the supercooled liquid against crystallization and the formation of the equilibrium crystalline phases with a high growth rate are responsible for their low glass-forming abilities (GFAs). Relatively low thermal conductivities of Ni-based alloys are also considered to be another factor to limit their GFAs. The GFA of the binary Ni65.5Zr34.5 alloy alloyed with 4% or 5% Al was enhanced, and a fully glassy rod with a diameter of 0.5 mm was formed.