Research On The Structure And Properties Of TiSiN,Ti-Al-N And TiSiN-Ag Composite Films

A series of TiSiN composite films with different Si contents,a series of TiAlN composite films with different Al contents and a series of TiSiN-Ag composite films with different Ag contents were prepared at room temperature by JGP-450 multi-target magnetron sputtering technique.The chemical components,microstructures,cross-section topography,oxidation resistances,microhardness,film-substrate bonding strengths,friction and wear properties were measured.A series of supercell models were built by Materials Studio and formation energies of point defects were calculated.The results are as follows.The research of TiSiN composite films shows that the TiN is composed of fcc TiN phase.The preferred orientation is c-TiN(111).The substitution solid solution of(Ti,Si)N is formed when the Si add in TiN film.Amorphous Si3N4 is formed when Si is more than solid solubility.The existence of a-Si3N4 can improve the oxidation resistance of TiSi N films.With the increase of Si content,the hardness and the elastic modulus of TiSiN films increase firstly and then decrease.An appropriate amount of Si can improve the bonding strength between the film and stainless steel substrate.When Si add into TiN film,the wear rate of TiSiN films decreased greatly.With the increasing of Si,the friction coefficient of TiSiN films is decreased at RT.The friction coefficient of TiSiN films increase at 800?.Si has no effect on the friction coefficient of TiN film when the temperature changes from 200? to600?.The research of Ti-Al-N composite films shows these results.When the content of Al is less than 25.72 at.%,the fcc TiN is the major phase in Ti-Al-N film.The preferred orientation is c-TiN(111).The substitution solid solution of(Ti,Al)N is formed when the Al add in TiN film.The hexagonal AlN phase appears when Al content is 25.72 at.%.With the increasing of Al,the hardness,elastic modulus and bonding strength increase.The wear rate decrease greatly,friction coefficient films increase.Al has no effect on the friction coefficient of TiN film when the temperature changes from 200? to 600?.When the Al content is more than 25.72 at.%,c-TiN disappears and h-AlN become the major phase.There is some c-AlN phase existing in film.Ti add into h-AlN phase forming the h-(Al,Ti)N solid solution.With the increasing of Al,the hardness of films is increased and the bonding strength decreased.The friction coefficient and wear rate decrease at RT.The friction coefficient decreases and wear rate increases at 800?.Al oxide into Al2O3 at high temperature.The existence of Al2O3 layer can improve the oxidation temperature of thefilm.The research of TiSiN-Ag composite films shows these results.When the Ag add into TiSiN composite films,Ag is in the independent phase form existing in film.When the content of Ag is 8.21 at.%,the fcc Ag(111)peak arise.The existence of Ag phase hinder the growth of TiN crystal.With the increase of Ag content,the hardness and elastic modulus of TiSiN-Ag composite films decrease.When the content of Ag is 20.34 at.%,the bonding strength between the film and stainless steel substrate reach to the maximum value of 14 N.With the increase of Ag content,the friction coefficient and wear rate of the films at RT are decreased.Silver is the lubricating material.