Deposition Of Thick Films By Large Arc Source Ion Plating And Its Application

Thick film more than 10 microns has significant demand in many industrial fields,such as nuclear power,aerospace,machinery,automotive,petrochemical,marine and other fields.Thick film can block internal defects connected or penetrate through,reduce the damage of defects to film performance effectively,with many advantages like wear resistance,corrosion resistance,antioxidant,longer consume aging.Such as nuclear fuel shell needs a thick film to improve its accident tolerance,high temperature antioxidant performance,and the service time;automotive engine piston ring works in high temperature,high pressure and reciprocating friction conditions,a thick wear film can improve its service age and wear performance significantly.Traditional thick film preparation techniques have been unable to meet the growing demand,such as plating and spraying.What's more,physical vapor deposition(PVD)technology can prepare high quality film,environment-friendly,especially arc ion plating(AIP)become the most potential technology among PVD technologies to prepare thick film.However,the preparation of thick film by AIP still faces to the difficulties of numerous metal droplets,large residual stress,and slow deposition rate.In order to solve these issues,arc source technology,materials and processes need an overall consideration,to reduce defect density while increasing thickness.A new large area arc source was co-developed by our team and Dalian Nano-crystal Technology Co.,Ltd.,which makes up disadvantages of traditional arc source,such as small working area,slow deposition rate,metal droplets,uneven magnetic field,and poor flexibility of target adjustment.The new arc source has advantages of a large working area,rapid deposition rate,multi-mode double magnetic fields,uniform and fast arc spot movement,and droplets less.It provides hardware foundation for thick film deposition.By modulating the parameters of the new large area arc source,the proper deposition parameters were obtained of rapid deposition,uniform denseness and few defects.This paper studies the deposition and binding force process of thick film suitable for new large area arc source.Combined with the requirement of surface protection as the main purpose,the nuclear Zr-4 alloy and SUS 304 are chosen as substrate material deposited on three types of thick film,including metal Cr monolayer,metal/ceramic Cr/CrN multilayer,and MAX phase Ti2AlC gradient ceramic film.Our results fully demonstrate the potential of the new large area arc source in the deposition of various thick films,summarized as below.The nuclear power industry is in urgent need of a surface technology to prepare excellent thick film,to improve the accident tolerance of nuclear fuel cladding,avoid the reaction of Zr alloy with high temperature water vapor to generate explosive hydrogen,the nuclear industry has a significant demand for thick film technology protecting the cladding.Using large area arc source,we have prepared a uniform,smooth,dense and 20 thick Cr film on the nuclear fuel cladding,with a deposition rate of 3.6 ?m/h(industrial deposition rate).A special high voltage rebombarding process is designed to make interface alloying with excellent binding force(>100 N),the thick film can withstand at least 15.8%of the shape variables without falling off,and withstand high temperature oxidation under simulated accident conditions(1000?.1100?and 1200? for 1 hour).After the most severe test(1200 0C/1 h),still remaining three layers:the chromium oxide layer on the surface,the residual Cr layer and the Cr-Zr diffusion layer on the Zr alloy substrate,it still remains about 6.8 ?m Cr layer well bound to the substrate forming an effective barrier;the large thickness can be consumed for multiple oxide film cracking;cracks,folds,voids and other defects formation mechanism is explained.The results are well demonstrated that large area arc source can rapidly prepare thick metal film,dense,uniform,and highly binding,and the nuclear fuel cladding can meet the requirements of regular and accident condition(>1000?)after deposited thick Cr film.Paper machine sieve blades work in the pulp containing gravel nails suffering from continuous wear,the conventional electroplating hard Cr thick film exposed low hardness,quick wear loss,poor oxidation and other shortcomings.Large area arc source is employed with multilayer design,a 42 thick Cr/CrN multilayer is deposited on the sieve blade(SUS 304).with an average deposition rate of 3.4 ?m/h(industrial deposition rate).The service behavior are tested under actual friction wear conditions,the coefficient of friction of Cr/CrN multilayer reduces from Cr monolayer 0.798 to 0.353,the wear width decreases from 320 ?m to 185 ?m,and the wear only stays at the surface of the thick film with abrasive wear characteristic.The Cr layer can effectively regulate the micro-hardness of the thick film,improved up to 18.4%,the binding force remains at an excellent level>60 N.The 42 ?m thick Cr/CrN multilayer is oxidized at a high temperature of 1000?(10 h),but the oxidation is confined within 2.3 ?m depth and cannot continue to destroy the substrate.N diffusion phenomenon presents in Cr/CrN multilayer,which is associated with high temperature deposition and high energy ion bombardment,and the N diffusion causes a gradient distribution of the hardness inside the thick film.The results indicate that large area arc source and process design can be used to deposit thick protective metal/ceramic thick film rapidly withstand harsh conditions,with the potential to replace traditional electroplating hard Cr.and the thick multilayer is applied on paper machine sieve blades.Preparation of Ti2AlC thick film with MAX phase structure on zirconium alloy component in nuclear reactor,has gradually become a research tendency to improve the accident tolerate performance.To avoid the introduction of H element to cause hydrogen brittleness,large area arc source combines with MF magnetron sputtering which controls graphite target,to obtain a 20 ?m dense Ti-Al-C thick film on the surface of Zr-4 alloy.After vacuum annealing at of 550 ?,650 0C,750 ? and 850?,the Ti2AlC structure can be synthesized at a minimum of 650 0C,and higher temperatures can accelerate the generation of Ti2AlC.High temperature deposition is essential for the preparation of Ti2AlC thick film.It is proved that large area arc source can combine other deposition techniques to deposit thick multicomponent ceramic film rapidly.