This study mainly attempts to develop Mg-based alloy materials with excellent corrosion resistance by means of multi-principal alloying. The alloy elements are determined based on the multi-principal alloy elements and the performance requirements of the components of biomaterials. Mg₃₀Zn₃₀Sn₃₀Sr₅Bi₅ alloy was successfully prepared by vacuum magnetic levitation melting. Through the electrochemical corrosion test with m-SBF solution (pH7.4) as the electrolyte, the corrosion rate of alloy Mg₃₀Zn₃₀Sn₃₀Sr₅Bi₅ alloy decreased to 20% of pure Mg. It could also be seen from the polarization curve that when the self-corrosion current density is low, the alloy shows superior corrosion resistance. Nevertheless, with the increase in self-corrosion current density, although the anodic corrosion performance of the alloy is obviously better than that of pure Mg, the cathode shows the opposite situation. The Nyquist diagram shows that the self-corrosion potential of the alloy is much higher than that of pure Mg. In general, under the condition of low self-corrosion current density, the alloy materials display excellent corrosion resistance. It is proved that the multi-principal alloying method is of positive significance for improving the corrosion resistance of Mg alloys.

This study focused on the design and the preparation method of a new biomaterial, Mg₃₀Zn₃₀Sn₃₀Sr₅Bi₅ (at%) alloy, and its simulation and property analyses. Based on the comprehensive consideration of the preparation of high-entropy alloys, the selection of biomaterial elements, and the existing research results of common Mg-based materials, the atomic percentage of various elements, that is, Mg:Zn:Sn:Sr:Bi = 30:30:30:5:5, was determined. Using the theoretical methods of thermodynamic performance analysis and solidification performance analysis, the proposed composition was simulated and analyzed. The analysis results showed that the mechanical properties of the new material can meet the design requirements, and it can be prepared in physical form. XRD, SEM, PSD, compression tests, and other experimental tests were conducted on the material, and the alloy composition and distribution law showed various characteristics, which conformed to the “chaotic” characteristics of high-entropy alloys. The elastic modulus of the material was 17.98 GPa, which is within the 0–20 GPa elastic modulus range of human bone. This means that it can avoid the occurrence of stress shielding problems more effectively during the material implantation process.

In this paper, the elliptical deformation mechanism of the bearing ring after quenching has been studied by using the theory of “metal-thermal-mechanical” and the multi-field coupling simulation method. It has been mainly considered that it occurred as an experimental phenomenon in the past that, when the bearing ring had been oil quenched, a vapor film had usually formed on its surface, and the breakage and boiling of the vapor film had been observed to be uneven in a circumferential direction. For this reason, based on the phase transition kinetics, several types of heat transfer boundary conditions on the outer surface of bearing rings during oil quenching have been assumed, and the multi-field coupled simulation of the quenching process of bearing rings has been carried out in this paper. According to the simulation results, it could be concluded that when two different heat transfer boundary conditions have been set on the outer surface of the bearing outer ring in the form of orthogonal symmetry, the quenched bearing outer ring would produce elliptical deformation. The above simulation results have been basically verified by comparing the experimental results.