Effect of Sn Addition in the Microstructure Refinement and Corrosion Resistance of Cu-Zr-Al-Ag Alloy

Abstract

In this paper, a composition of known high glass-forming ability, Cu 42 Zr 42 Al 8 Ag 8 and a novel Cu 42 Zr 42 Al 8 Ag 4 Sn 4 , were produced by suction-casting. After rapid solidification of both alloys, X-ray diffraction patterns along with crystallite size estimation by Scherrer equation and scanning electron microscopy images revealed a refined microstructure, composed mainly by AlCu 2 Zr, CuZr 2 and Cu 10 Zr 7 phases. Transmission electron microscopy indicated the presence of small crystalline precipitates in the Cu 42 Zr 42 Al 8 Ag 4 Sn 4 suction-casted sample. Polarization curves showed a higher passivation current in the Sn containing sample, suggesting a decrease in corrosion resistance.

Copper Based Bulk Metallic Glasses for Medical Devices

“…The microscopic image of the arc melted Cu45Zr45Al5Ag5 alloy ( Figure 6) presents two compounds with distinct shapes precipitated in the matrix. Different studies [5,16] reported the presence of structures similar to those presented in this research. After casting, the structure is refining, but does not substantially change (Figure 7).…”

“…The samples were obtained by copper mold casting and their structure and properties were investigated using X-Ray diffraction (XRD), differential scanning calorimetry (DSC) and optical microscopy.Biocompatible materials play a key role in the construction of medical devices currently used on a large scale [1][2][3][4]. Recent researches were focused on developing new materials that would not inherit the disadvantages of the classic materials (poor corrosion resistance, low deformability etc) [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Bulk metallic glasses (BMG) can be a viable alternative for replacing classic biocompatible materials [18,19], due to their specific properties such as: good corrosion resistance in the absence of intercrystalline corrosion, excellent plastic deformability and good castability (absence of casting defects and voids that form when casting crystalline structure materials) even with complex geometries.…”

“…This sum of properties makes the BMGs very appealing for medical devices.After the first metallic glass of Au75Si25 was developed in the 1960's [11], intensive research were conducted in order to obtain BMGs using different elements including Zr, Ni, Ti, Fe, Au, Pt, Cu as a base for these outstanding materials. Various methods of obtaining BMGs were developed, dealing with problems related to raw materials (their purity), complicated equipment and process, mechanical properties of the products (generally the BMGs are brittle) [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Recent studies are focused on discovering new alloying strategies including new materials combinations, processing methods, new structures (nanocrystalline or nanoquasicrystalline particles) as well as exploring new properties (such as magnetic, chemical or physical).This study was aimed to assess the influence of silver on the structure and properties of bulk metallic glasses with biocompatible properties from the Cu-Zr-Al respectively Cu-Zr-Al-Ag system.…”