Significance of Aluminum on Hardness of Titanium Aluminum Nitride Deposited by Magnetron Co‐Sputtering

Ti _{1− x} Al _x N films were synthesized by reactive magnetron co‐sputtering with different aluminum compositions. X‐ray diffraction, secondary ion mass spectrometry, nanoindentation, and atomic force microscopy (AFM) techniques were used to analyze these films. The as‐deposited films were crystalline for concentrations of Al (35%, 40%, 55%, and 64%) and at 81% it became amorphous. Nanoindentation hardness increases with aluminum and started to decrease beyond 81% of aluminum. Continuous multicycle indentation technique is used to analyze the failure mode of the film with highest hardness. AFM topography analysis of this film exhibited edge cracks outside and inside the indentation area and sink‐in when the penetration reaches the substrate.