Atomistic simulations of the surface severe plastic deformation-induced grain refinement in polycrystalline magnesium:The effect of processing parameters

Magnesium(Mg)based alloys are promising candidates for many applications,but their untreated surfaces usually have low strength and hardness.In this study,a single point diamond turning(SPDT)technique was applied to refine the grain size and improve the mechanical properties of the surface layers of Mg-Li alloys.By refining grains in the topmost layer to the nanometer scale(~60 nm),the surface hardness was found to be enhanced by approximately 60%.The atomic plastic deformation process during the SPDT was then studied by the real-time atomistic molecular dynamics(MD)simulations.A series of MD simulations with different combinations of parameters,including rake angle,cutting speed and cutting depth,were conducted to understand their influences on the microstructural evolution and associated plastic deformation mechanisms on the surface layer of the workpieces.The MD simulation results suggest that using increased rake angle,cutting speed and cutting depth can help to achieve better grain refinement.These simulation results,which provide atomic-level details of the deformation mechanism,can assist the parameter design for the SPDT techniques to achieve the high-performance heterogeneous nanostructured materials.

Biomaterial types,properties,medical applications,and other factors:a recent review

Biomaterial research has been going on for several years,and many companies are heavily investing in new product development.However,it is a contentious field of science.Biomaterial science is a field that combines materials science and medicine.The replacement or restoration of damaged tissues or organs enhances the patient’s quality of life.The deciding aspect is whether or not the body will accept a biomaterial.A biomaterial used for an implant must possess certain qualities to survive a long time.When a biomaterial is used for an implant,it must have specific properties to be long-lasting.A variety of materials are used in biomedical applications.They are widely used today and can be used individually or in combination.This review will aid researchers in the selection and assessment of biomaterials.Before using a biomaterial,its mechanical and physical properties should be considered.Recent biomaterials have a structure that closely resembles that of tissue.Antiinfective biomaterials and surfaces are being developed using advanced antifouling,bactericidal,and antibiofilm technologies.This review tries to cover critical features of biomaterials needed for tissue engineering,such as bioactivity,self-assembly,structural hierarchy,applications,heart valves,skin repair,bio-design,essential ideas in biomaterials,bioactive biomaterials,bioresorbable biomaterials,biomaterials in medical practice,biomedical function for design,biomaterial properties such as biocompatibility,heat response,non-toxicity,mechanical properties,physical properties,wear,and corrosion,as well as biomaterial properties such surfaces that are antibacterial,nanostructured materials,and biofilm disrupting compounds,are all being investigated.It is technically possible to stop the spread of implant infection.