Performance analysis of twin-layer AlTiN and TiCN coated inserts during high speed turning of SS304 with synthetic coolant at 0°C

Industries are facing challenges to machine hard materials in economical ways and to improve the output machining characteristics. In pursuit of effective problem-solving, two distinct sets of AlTiN and TiCN coated inserts were meticulously prepared. Their respective performances were subsequently compared, using the output machining parameters as reference points. AlTiN inserts are fabricated by applying a twin layer consisting of Al50Ti40N (2 µm thickness) and Al60Ti50N (3 µm thickness) over the substrate. The insert obtained from this process has exceptional strength and remarkable toughness. Another substrate is coated with a 3 µm thick layer of TiCN, as TiCN coating offers excellent resistance against shock loads and impact stress. Previous research conducted by scholars has already established the efficacy of using synthetic coolant at 0°C for machining SS304. Hence, synthetic coolant was employed in combination with the aforementioned two types of inserts during their performance testing. A comprehensive analysis revealed that the performance of twin-layer AlTiN inserts surpassed that of TiCN inserts, showcasing superior tool life, reduced tool wear, and enhanced surface finish quality. The replacement of TiCN inserts with AlTiN inserts resulted in an impressive increase of around 70% in tool life and approximately 30% in surface finish quality.