Effects of Cu Content on Microstructures and Mechanical Properties of Ti-Ni-Based Amorphous Composites

Abstract:

Ti-Ni-based amorphous composite samples (Ti0.5Ni0.5)100-XCuX with the same CuX but the different diameters which had been prepared successfully by the copper mold suction casting were used to study the effect of their Cu contents (X=0, 10, 15, 20, 25, 30, 35 and 40) on the microstructures and mechanical properties of such amorphous composites. The results show that both fracture strength and plastic strain of the alloy are very high while the copper content is x=20. And the alloy exhibits the best comprehensive properties. As the x values increase, the glass forming ability of (Ti0.5Ni0.5)100-XCuX alloy shows a waveform change from increasing to decreasing and then to increasing, but following an overall trend towards decreasing. The plasticity of Ti-based amorphous materials can be improved by adding Cu element in modest quantities (x = approx. 25) to the Ti-Ni-based composites; however adding more numbers (i.e., x > 30), neither can improve the amorphous forming ability nor can enhance its strength. When x = 15, the alloy has the highest breaking strength of 2,440 MPa while reach the higher yield strength of 1471 MPa and cause a 17.15% plastic strain. The data are pretty high with respect to other amorphous systems or other alloy systems with memory of their shapes. When x = 25, there is a certain increase in the alloy plastic strain, whereas underwent a 21.35% plastic deformation.

Key words:Armophous composites; Cu content; microstructure; mechanical property