Mechanical Properties And Microstructure Of AlN/SiCN Nanocomposite Coatings Prepared By R.F.-Reactive Sputtering Method

Abstract

FIn this work, AlN/SiCN composite coatings were deposited by r.f.-reactive sputtering method using a facing target-type sputtering (FTS) apparatus with composite targets consisting of Al plate and SiC chips in a gaseous mixture of Ar and N2, and investigated their mechanical properties and microstructure. The indentation hardness (HIT) of AlN/SiCN coatings prepared from composite targets consisting of 8 ~32 chips of SiC and Al plate showed the maximum value of about 29~32 GPa at a proper nitrogen gas flow rate. X-ray diffraction (XRD) patterns for the AlN/SiCN composite coatings indicated the presence of the only peeks of hexagonal (B4) structured AlN phase. AlN coatings clarified the columnar structure of the cross sectional view TEM observation. On the other hand, microstructure of AlN/SiCN composite coatings changed from columnar to equiaxed structure with increasing SiCN content. HR-TEM observation clarified that the composite coatings consisted of very fine equiaxial grains of B4 structured AlN phase and amorphous phase.

Keywords

• AlN
• SiCN
• XRD
• sputtering
• TEM