Magnesium alloy, as an absorbable and implantable biomaterial, has been greatly developed in the application field of biomaterials in recent years due to its excellent biocompatibility and biomechanics. However, due to the poor corrosion resistance of magnesium alloy in the physiological environment, the degradation rate will be unbalanced, which seriously affects the clinical use. There are two main ways to improve the corrosion resistance of magnesium alloy: one is by adding alloying elements, the other is by surface modification technology. Compared with adding alloy elements, the surface coating modification has the following advantages: (1) The surface coating modification is carried out without changing the matrix elements of magnesium alloy, avoiding the introduction of other elements; (2) The corrosion resistance of magnesium alloy can be improved by relatively simple physical, chemical, or electrochemical improvement. From the perspective of corrosion resistance and biocompatibility of biomedical magnesium alloy materials, this paper summarizes the application and characteristics of six different surface coating modifications in the biomedical magnesium alloy field, including chemical conversion method, micro-arc oxidation method, sol-gel method, electrophoretic deposition, hydrothermal method, and thermal spraying method. In the last section, it looks forward to the development prospect of surface coating modification and points out that preparing modified coatings on the implant surface combined with various modification post-treatment technologies is the main direction to improve biocompatibility and realize clinical functionalization.

In recent years, along with the development and application of magnesium alloys, magnesium alloys have been widely used in automotive, aerospace, medicine, sports, and other fields. In the field of medical materials, magnesium not only has the advantage of light weight, high strength, and a density similar to that of human bone, but also has good biocompatibility and promotes the growth of human bone. However, the mechanical properties and corrosion resistance of magnesium alloys need to be further improved to meet the requirements for human biodegradable implants. In this study, three alloys (mass fractions: Mg–10Zn, Mg–20Zn, and Mg–30Zn (wt.%)) were prepared using powder metallurgy by homogeneously mixing powders of the above materials in a certain amount with magnesium as the substrate through the addition of zinc elements, which also have good biocompatibility. The effect of zinc on the microstructure, mechanical properties, wear performance, and corrosion resistance of magnesium–zinc alloys was studied when the zinc content was different. The results show that compared with the traditional magnesium alloy using powder metallurgy, prepared magnesium alloy has good resistance to compression and bending, its maximum compressive stress can reach up to 318.96 MPa, the maximum bending strength reached 189.41 MPa, and can meet the mechanical properties of the alloy as a human bone-plate requirements. On the polarization curve, the maximum positive shift of corrosion potential of the specimens was 73 mv and the maximum decrease of corrosion-current density was 53.2%. From the comparison of the above properties, it was concluded that the three prepared alloys of which Mg–20% Zn had the best overall performance. Its maximum compressive stress, maximum bending strength, and corrosion-current density reached 318.96 MPa, 189.41 MPa and 2.08 × 10⁻⁵ A·cm⁻² respectively, which are more suitable for use as human implant bone splints in human-body fluid environment.

The high humidity of marine atmosphere and the existence of corrosive chloride ions lead to the premature corrosion failure of aluminum alloy components. The development of surface-strengthening technology provides an opportunity to prolong their service life spans. As a mature surface-strengthening technology, the shot peening process is widely used, owing to its advantages over other strengthening technologies, including its easy operation and high production rate. The shot-peened surface integrity depends on shot peening variables that introduces the thermomechanical effect to the deformed surface layer. When the inappropriate shot peening parameters are adopted, the shot-peened surface integrity could be deteriorated, which further weakens the corrosion performance of the surface. Therefore, it is essential to optimize shot peening process variables with the consideration of the material and its application. In this paper, the strengthening mechanism of the shot peening process was firstly elaborated, and then the effects of process parameters on the surface integrity of aluminum alloy were reviewed. The relationship between the surface integrity and corrosion resistance was also revealed. Two directions, including the application of the surface temperature rise during the shot peening process and the shot-peened surface roughening, are proposed.

The magnesium alloys Mg-0.5Mn-2Zn, Mg-1.0Mn-2Zn, and Mg-1.5Mn-2Zn (wt.%) with potential biomedical applications, synthesized by powder metallurgy, were investigated to evaluate the influence of manganese content on their microstructure, mechanical properties, and corrosion resistance. The results show that Mg-Mn-Zn alloys prepared by powder metallurgy reached the maximum compressive stress of 316 MPa and the maximum bending strength of 186 MPa, showing their good resistance to compression and bending, and meeting the mechanical properties required for the human bone plate. With an increase in manganese content, the corrosion resistance improved. In the polarization curve, the maximum positive shift of corrosion potential was 92 mV and the maximum decrease of corrosion current density was 10.2%. It was concluded that, of the alloys tested, Mg-1.0Mn-2.0Zn (wt.%) had the best overall performance, and its maximum compressive stress force and corrosion current density reached 232.42 MPa and 1.32 × 10⁻⁵ A·cm⁻², respectively, being more suitable for service in human body fluids.

High-speed machining of γ-TiAl alloy is a significant challenge due to high cutting temperatures. From the perspective of environmental protection and improving tool life, appropriate cooling strategies should be adopted. Compared with dry and conventional flood cooling conditions, the feasibility of machining γ-TiAl in cryogenic LN₂ cooling conditions was discussed. The cutting force, tool wear and its mechanism, and surface roughness, as well as sub-surface morphology characteristics, were studied by combining macro and micro techniques. The results revealed that the wear morphology of the rake and flank face under the three cooling media shows different degrees. The crater wear of the rake face is expanded at high speeds and then progresses into more serve flaking and notching wear. The main wear pattern on the flank face is gradually transformed from adhesive wear to diffusion and oxidation wear at high speeds in dry machining. In the LN₂ condition, the diffusion of workpiece elements and cutting-edge oxidation were restrained. The wear pattern is still mainly adhesive wear. In addition, cryogenic machining shows significant advantages in reducing cutting force, suppressing heat-affected zone, improving surface quality, and inhibiting micro-lamellar deformation.