Performance evaluation of coated carbide tools and machinability investigation of AISI D7 cold work tool steel in turning under dry environment

The present work explores a comparative investigation on the cutting performance of AlTiSiN and AlTiN-coated carbide tools during the dry turning of AISI D7 cold work tool steel, an area that has acknowledged limited attention in the literature. The performance of both coatings was assessed by conducting cylindrical turning trials with different cutting parameters, including cutting speed, feed rate and depth of cut. The assessment was based on important machinability indicators like flank and crater wear, chip morphology, cutting force, machined surface quality and cutting temperature. The experimental results showed that the AlTiSiN-coated tool consistently outperformed the AlTiN-coated tool by producing better surface finish, lower cutting force and temperature, better chip morphology and reduced tool wear. Moreover, the AlTiSiN-coated insert achieved an improvement of almost 28% in tool life than the AlTiN-coated insert, thereby proving its improved wear resistance and machining performance. These findings indicate that AlTiSiN coating offers not only enhanced cutting performance but also a more economical and reliable recommendation for dry turning application.