Study of dry sliding wear and corrosion behavior of nanocomposite Al-Si-N coated steel

The present investigation evaluates the wear and corrosion performance of Al-Si-N coated and uncoated steel substrates. The magnetron sputtering technique was used to develop the optically transparent nanocomposite AlSi-N coating over the steel substrate. The Al-Si-N coating was the composite of a polycrystalline phase of wurtzite (hexagonal) AlN and the amorphous phase of Si3N4. The steel's surface hardness value was enhanced significantly by the Al-Si-N coating. The coated steel exhibited -19 GPa hardness value, whereas uncoated steel has -6 GPa. The wear performance testes of the coated and uncoated steels, examined by the ball on disc tribometer, marks 60% less wear of the coated steel than the uncoated steel at 2 N loads. The coated steel wear out by chipping and pull-out abrasive mechanism. The potentiodynamic polarization study indicates improved barrier property and adhesion of the coating than the passive film on the steel with a similar corrosion current value of -10 nA/cm2. The corrosion performance of the uncoated steel (SS 304) did not deteriorate with the Al-Si-N coating. Our analysis-based observations conclude that the nanocomposite Al-Si-N coating exhibits a unique combination of optically transparency, high wear, and corrosion resistance, making Al-Si-N a potential protective candidate for solar panels, optoelectronic devices, automotive shields, and optical devices.