Production and Comparison of Adapted Load-Sensitive Magnesium Alloys

Magnetic magnesium alloys can be utilised as a load sensitive material, in which the inverse magnetostrictive effect is used in order to measure the actual loads in structural components manufactured from such lightweight sensor alloys. To achieve a material which exhibits magnetic properties, magnesium is alloyed with ferromagnetic materials like cobalt or samarium-cobalt. In order to improve the mechanical properties of these alloys, alloying elements commonly used with Mg must be utilised, which however may have a slight negative impact on the magnetic sensitivity. In this work, two separate magnetic Mg alloys are compared, each with properties matched to the opposing requirements: (a) high load sensitivity and (b) satisfactory mechanical properties, respectively. The precipitation behaviour of the ferromagnetic constituent cobalt in magnesium is briefly shown on the basis of SEM images of a binary Mg-Co alloy. Cyclic loading tests employing harmonic analyses of eddy current signals are utilised in order to verify the alloys’ sensory properties. The mechanical properties are investigated using tensile tests.