Study On The Preparation Of Long-acting Antibacterial Stainless Steel By Plasma Alloying And Hardening Of Ag(Cu) On The Surface Of Plasma

The research of antibacterial stainless steel became an attractive field in domestic research institutes and universities for the spreading of anti-microbe conception and lacking of hygiene products in last ten years.There are two means to design antibacterial stainless steel nowadays,designing for integral type and external type antibacterial stainless steel.Double glow plasma alloying treatment was used to form the anti-bacterial film.Active screen plasma nitriding and carbonizing treatment was used to harden the film in order to achieve the purpose of designing an antibacterial stainless steel with a nice wear resistance on the while.In the research,I must to solve the questions as follows.To get the disposition behavior of copper by designed some coppering experiment.How parameters of cathode voltage in sputtering period,furnace pressure and silvering temperature affect the film with silver in the next silvering treatment.To find the relationship of silver area rate and silver content.To acquire the influence of different sequence of silvering and nitriding&carbonizing craft.Different pretreatment methods and silvering craft cycle to affect the nitriding and carbonizing process were investigated.Finally studied the feasibility of low temperature silvering treatment.The wear resistance performance was evaluated by friction and wear experiment;the corrosion resistance performance was appraised by static soaking corrosion experiment.The result showed as follows.The copper atomic group covered on the stainless steel in exploration experiment of bad film adhesion.Finally choose the silvering treatment as a main craft.The pretreatment of shot blasting can ensure nice film adhesion and comprehensive performance,the real Ag content on samples surface is between 1%and 2%.The change trend with real Ag content and design Ag content were same.I found the optimum craft:cathode voltage in sputtering period was 750 V;furnace pressure was 30 Pa;silvering temperature was 890?.It found that six cycle silvering+nitriding and carbonizing treatment cannot rise the hardness of stainless steel with silver.So I decreased the cycle and made a contrast of 1 cycle and 2 cycles.The data as follows.The samples by 1 cycle silvering+nitriding and carbonizing treatment:atoms and atomic groups accumulates tightly,the film and the substrate showed metallurgical bonding.The film thickness was about 3?m;surface micro-hardness was659.3HV0.05,15s,a rise about 1 times than stainless steel;the result of Rockwell binding strength was HF1;the wear rate was 12.08×10^-6 mm³·N^-1·m^-1 decreased from stainless steel of 17.9×10^-6mm³·N^-1·m^-1.The samples by 2 cycle silvering+nitriding and carbonizing treatment:similar surface topography with 1 cycle;the film thickness was about 5 ?m;surface micro-hardness was 624.4HV0.05,15s,the hardness was narrowly below than 1 cycle;the result of Rockwell binding strength is HF5;the wear rate of 8.75×10^-6 mm³·N^-1·m^-1 decreases from stainless steel of 17.9×10^-6 mm³·N^-1·m^-1.The comprehensive performance of 1 cycle was better than 2 cycle.The design to form thin long lasting antibacterial stainless steel was feasible.Low temperature silvering treatment can deposit the silver film on nitriding and carbonizing process on the while.The micro-hardness is 971.9 HV0.05,15s,a composite by silver film and harden film,nearly two times than stainless steel.the result of Rockwell binding strength is HFl;the wear rate of 0.833×10^-6mm³·N^-1·m^-1 decreased from stainless steel of 17.9×10^-6 mm³·N^-1·m^-1.Though the hardness and wear resistance improved much but the shortage of long deposition time was un-neglectable.