Microstructure and Magnetic Properties of Cobalt and Zinc Containing Magnesium Alloys

The magnetic properties of lightweight alloys based on magnesium and cobalt offer a novel way to measure mechanical loads throughout the entire structural component using the magnetoelastic effect. Since the solubility of cobalt in the magnesium matrix is negligible, the magnetic properties mainly originate from Co-rich precipitates. Size and distribution of the Co-containing phases within the alloy's microstructure can be influenced during the initial processing method of the alloy. Specifically, the cooling rate in the casting processes has a major influence on the resulting magnetic properties. In this study, Mg-Co-based alloys were produced by several casting methods which feature substantially different cooling rates, i.e. gravity sand casting, gravity die casting and high-pressure die casting. The differences between the manufactured alloys’ micro- and phase structures are compared and the superior magnetic and mechanical properties of the high-pressure die cast material are demonstrated

Material-inherent Data Storage Using Magnetic Magnesium-cobalt Alloys

Magnetic magnesium alloys have an inherent load-sensitive behavior. These alloys are manufactured by casting of magnesium alloyed with the ferromagnetic element cobalt. In this context, the magnetoelastic effect can be used in order to measure mechanical loads during the component's service by means of a harmonic analysis of eddy current signals. The utilization of magnetic magnesium as a load-sensitive material in order to measure mechanical loads in structural components has been demonstrated in previous works. Another application is the magnetic labeling of the alloy. In this context the magnetic remanence is a significant characteristic value. A data track can be written directly on the material's surface by means of an electromagnetic write head. The track may contain relevant component-specific information like serial numbers, manufacture date and expected lifetime. This information can be read out by means of a sensor utilizing the giant magnetoresistive (GMR) effect. The magnetic labeling in relation to the manufactured alloy and the cooling rate during the casting process is examined in this work. The magnetic labeling of three alloys based on magnesium, cobalt and zinc has been investigated; these are MgCo4 and MgCo4Zn2. The alloys’ mechanical as well as their magnetic properties are significantly influenced by these additional alloying elements. In order to investigate the alloys’ suitability for magnetic data storage the quality of the data tracks read out using a GMR sensor are compared depending on the alloy composition. The magnetic labeling is influenced by the microstructure regarding solidification and cooling rate. A conical casting geometry with different solidification rates in top and bottom sections was used for an examination of the relationship between the density of the magnetic phases and the quality of the magnetic labeling

The Concept of Technical Inheritance in Operation: Analysis of the Information Flow in the Life Cycle of Smart Products

AbstractIndustry 4.0 opens great potentials in productions technologies by establishing communication between machines and equipment as well as processes along the life cycle of products. Within the Collaborative Research Center (CRC) 653 several aspects of the design and application of communicative and intelligent systems and components are demonstrated. The CRC aims to enable smart products, so-called gentelligent components, to give feedback to the product and production processes based on inherently stored information.This work continues a series of publications regarding the development of the concept of Technical Inheritance. Here, the process of Technical Inheritance is applied to improve gentelligent components. This was realized according to the biological principle to transfer hereditary information on the basis of evolutionary mechanisms and variations of the information transfer.To provide an efficient information management throughout the life cycle of components and to transfer relevant information from the current generation of the component to the next generation a unified closed data exchange format GIML was developed. At the example of a load-sensitive magnesium wheel carrier of the racing car RP09 this approach is demonstrated: the information flows over the life cycle are analyzed, the concept of Technical Inheritance applied and its advantages discussed

Influence of Cobalt on the Properties of Load-Sensitive Magnesium Alloys

In this study, magnesium is alloyed with varying amounts of the ferromagnetic alloying element cobalt in order to obtain lightweight load-sensitive materials with sensory properties which allow an online-monitoring of mechanical forces applied to components made from Mg-Co alloys. An optimized casting process with the use of extruded Mg-Co powder rods is utilized which enables the production of magnetic magnesium alloys with a reproducible Co concentration. The efficiency of the casting process is confirmed by SEM analyses. Microstructures and Co-rich precipitations of various Mg-Co alloys are investigated by means of EDS and XRD analyses. The Mg-Co alloys’ mechanical strengths are determined by tensile tests. Magnetic properties of the Mg-Co sensor alloys depending on the cobalt content and the acting mechanical load are measured utilizing the harmonic analysis of eddy-current signals. Within the scope of this work, the influence of the element cobalt on magnesium is investigated in detail and an optimal cobalt concentration is defined based on the performed examinations