Tribocorrosion Performance Of 304 Stainless Steel In Simulated Oral Environment

Stainless steel is widely used in artificial joints,splints for fracture joints,artificial heart valves and implanted prostheses due to its excellent corrosion resistance,high mechanical strength and low price.In the oral cavity,stainless steel is mainly used to make brackets,archwires,and crowns.However,the human oral environment is very complicated.Human saliva is a colorless,odorless,and odorless liquid.It is acidic and removes moisture.In addition to 80% water,it also contains Na+,K+,Ca2+,Cl-,HCO3-ions and some gas molecules.It also contains organic substances such as mucin and mucopolysaccharide.Studies have shown that human saliva can cause corrosion of stainless steel,accelerate the release of metal ions and cause serious allergic reactions.In addition,due to the widespread use of fluoride-containing oral cleaning products,the presence of fluoride ions may affect the corrosion behavior of stainless steel in the mouth.Moreover,current daily consumption of soft drinks such as cola and fruit juice may also cause serious corrosion of stainless steel.However,most of the current studies only focus on the corrosion properties of stainless steel in the oral environment,and rarely involve the study of the correlation between corrosion and wear.Thus,in this paper,the effect of fluoride ion concentration in artificial saliva on the corrosion and wear performance of stainless steel is discussed.The corrosion and wear performance of stainless steel materials in coke and soda soft drinks is also investigated.The possible synergy effect between friction and corrosion is discussed.The following results are achieved:(1)The effects of external experimental conditions(load,sliding frequency and sliding time)on the corrosion and wear performance of 304 stainless steel in artificial saliva environment were discussed.It is found that the mechanical friction movement obviously affected the corrosion and wear performance of 304 stainless steel in artificial saliva.The wear rate in artificial saliva increases with the increase of sliding frequency and sliding time,and increases first and then decreases with the increase of applied load.(2)The effect of fluoride ion concentration in artificial saliva on the corrosion and wear properties of stainless steel was discussed,and its corrosion and wear mechanism was analyzed.The experiment found that the corrosion current of stainless steel in artificial saliva first increased and then decreased with the increase of fluoride ion concentration.When the fluoride ion concentration was 0.25wt%,the corrosion current was the largest.The wear volume increases with the increase of the applied potential and decreases with the increase of the fluoride ion concentration.Under the condition of high potential and low fluoride ion concentration,the synergy between corrosion and wear is the strongest.(3)Discuss the corrosion and wear performance of 304 stainless steel in soft drinks,and analyze its friction and wear mechanism,wear and synergy.The experiment found that 304 stainless steel exhibited different corrosion properties in different corrosive media.With the increase of the applied potential,the corrosion current and wear of stainless steel tend to increase,and the wear is the largest in cola media.As the p H decreases,the wear and corrosion mechanism moves from wear-dominated to corrosion-dominated.As the applied potential increases,the wear and corrosion loss moves from low loss to high loss.As the applied potential increases,the synergy of wear and corrosion moves from low to high synergy.