• Cieślak, Grzegorz
• Chlewicka, Monika
• Mizera, Jarosław

Abstract

The structure of materials is extremely interesting and broad topic. This is due to the fact that it is possible to link it to the properties of the materials. By knowing the exact impact of a particular microstructure on the properties of the alloy, it is possible to better understand the processes occurring within the material and it enables the perfect design of materials with desired properties. Metallic materials typically have a crystalline structure. It is described as a long-distance order, manifested by geometrically ordered arrangement of the atoms resulting in lattice structure. But this is not the only structure present in metal alloys. They may also exist in an amorphous form. Amorphous state is characterized by short-range ordering but lacking long range order within the lattice. Properties of metallic materials mainly depend on the microstructure. That is why it so important whether it will be fully crystalline, mixed or completely amorphous. Properties of amorphous materials in fact, may be much different than the properties of their counterparts with crystalline or mixed structure [1-2]. In recent years, more and more interest is placed on Mg-Zn-Ca alloys [1-3]. This is due to their physical and mechanical properties, which may include: a low density, high strength and high ductility [4-5]. High popularity of these alloys is also affected by their biological properties such as biocompatibility and bioresorbability [1]. In addition, these materials are characterized by a relatively low price.Taking into account the abovementioned, in this research, an attempt will be made to find the relationship between the structure of the analyzed Mg67Zn29Ca4 alloy and their corrosion resistance under physiological conditions. Mg67Zn29Ca4 alloy were prepared using high purity elements (99,99%) in a vacuum armosphere. Rods with 3 mm diameter were obtained using cooper mould casting method. Samples were cut to 3 mm long rods and than annealed in fixed temperature with different times. The parameters of the annealing process are important due to fact they allow to control the structure of the materials. After annealing the x-ray difraction (XRD) was carried out. Diffraction techniques were used to determine whether the alloy has a crystalline, mixed or fully amorphous structure. The corrosion rate under physiological condition was tested by the immersion test. The effect of material’s structure on corrosion resistance was determined. According to experimental results, the corrosion resistance of the rapid solidified Mg67Zn29Ca4 smples changes with structure.

Topics

• density
• impedance spectroscopy
• microstructure
• amorphous
• corrosion
• x-ray diffraction
• strength
• casting
• annealing
• ductility
• biocompatibility