Mechanical properties of the ice I–magnesium sulfate eutectic: A comparison with freshwater ice in reference to Europa

Abstract

A systematic series of experiments on laboratory grown ice I–magnesium sulfate (MgSO4·11H2O or MS11) eutectic columnar material and freshwater columnar ice at T=98K and T=263K directly compare some elastic and inelastic properties of these two materials. The results indicate: (i) that the ice I–MS11 eutectic columnar material (below simply as I–MS11) exhibits bulk elastic properties that are comparable to those of freshwater columnar ice (FWI) at T=263K; (ii) that I–MS11 is about 1.6 times stronger under bending, about 1.9 times stronger under compression within the brittle regime and about 1.3 times tougher than FWI at T=263K; (iii) that I–MS11 possesses a compressive flow strength within the ductile regime that is about one-half that of FWI at T=263K; (iv) that I–MS11 exhibits a transition from ductile-to-brittle behavior at a strain rate that is a factor of about 50 higher than that of FWI at T=263K; (v) that I–MS11 has a higher coefficient of kinetic friction at lower temperatures (T=98K) and a lower coefficient of kinetic friction at higher temperatures (T=263K) and higher sliding velocities (>10−5ms−1) compared to FWI. In other words, the results indicate that the mechanical properties of I–MS11 eutectic columnar material are generally comparable to those of freshwater columnar ice, under the conditions examined.