Cu/Ti base multicomponent amorphous Cu47Ti33Zr11Ni8Si1 and nanocrystalline silver composites

Abstract

AbstractAn easy glass‐forming alloy based on Cu–Ti of composition Cu47Ti33Zr11Ni8Si1 was ball milled for 40 h to obtain amorphous powder. X‐ray diffraction and differential scanning calorimetry (DSC) measurements confirmed the dominant presence of the amorphous phase after ball milling. However, transmission electron microscopy from powders allowed identification of Si particles and intermetallic phases a few nanometre in diameter, often of CuNi2Ti or Cu–Ti structures. The powder was then hot pressed in vacuum at temperature of 460 °C between the glass transition and the crystallization point to form bulk amorphous samples. Composites were prepared in the same way from mixed milled amorphous powders and nanocrystalline silver powder prepared by ball milling. Various ratios of amorphous to silver powder were applied with a maximum of 60% of nanocrystalline silver The microhardness of the amorphous phase component was near 1100 HV, much higher than the 90 HV of silver. Composites containing 20% of nanosilver have shown a much higher compression strength of 850 MPa, as compared to the 450 MPa of the composite containing 60% of silver, however, the latter has better ductility, near 5%, before fracture.