Effect of Rolling Treatment on Microstructure, Mechanical Properties, and Corrosion Properties of WE43 Alloy

Abstract

Magnesium alloys show broad application prospects as biodegradable implanting materials due to their good biocompatibility, mechanical compatibility, and degradability. However, the influence mechanism of microstructure evolution during forming on the mechanical properties and corrosion resistance of the magnesium alloy process is not clear. Here, the effects of rolling deformation, such as cold rolling, warm rolling, and hot rolling, on the microstructure, mechanical properties, and corrosion resistance of the WE43 magnesium alloy were systematically studied. After rolling treatment, the grains of the alloy were significantly refined. Moreover, the crystal plane texture strength and basal plane density decreased first and then increased with the increase in rolling temperature. Compared with the as-cast alloy, the strength of the alloy after rolling was significantly improved. Among them, the warm-rolled alloy exhibited the best mechanical properties, with a tensile strength of 346.7 MPa and an elongation of 8.9%. The electrochemical experiments and immersion test showed that the hot working process can greatly improve the corrosion resistance of the WE43 alloy. The hot-rolled alloy had the best corrosion resistance, and its corrosion resistance rate was 0.1556 ± 0.18 mm/year.

Investigating mechanical deformation’s role in cochlear implant durability

“…As a result, electrochemical processes were weakened and corrosion rates were reduced in highly deformed samples [ 18 ]. In the work of Deng et al, the WE43 alloy also showed better corrosion resistance in the hot rolled specimens [ 17 ].…”

“…Often a positive effect is reported, when smaller grain size leads to a finer distribution of precipitates at grain boundaries, e.g. [ 17 ]. Obviously, this is not an issue for the high-purity platinum.…”

“…The situation is, however, different for other biocompatible materials, where it was shown that use of appropriate rolling parameters and heat treatment can result in grain refinement and affect corrosion resistance. For instance the strength of the magnesium alloys WE43 is reported to increase as the rolling temperature increases, and tailored heat treatments result in improved corrosion resistance [ 17 ]. Other materials, such as cold rolled tantalum/tungsten alloys also show significantly less dissolution than the undeformed reference samples [ 18 ].…”

Optimizing the Rolling Process of Lightweight Materials

“…The cold rolling of magnesium alloys leads to a high density of dislocations and deformation twins, significantly contributing to strain hardening. This process can adversely affect the anisotropic behavior due to the development of a strong basal texture [10,11]. However, the strain hardening from cold rolling also increases the yield strength and tensile strength of the Mg alloys.…”