Abstract. Selective laser melting(SLM) and direct metal laser sintering(DMLS) are preferred additive manufacturing processes in producing complex physical products directly from CAD computer data, nowadays. The advancement of additive manufacturing promotes the design of internally cooled cutting tool for effectively used in removing generated heat in metal machining. Despite the utilisation of SLM and DMLS in a fabrication of internally cooled cutting tool, the level of accuracy of the parts produced remains uncertain. This paper aims at comparing the dimensional accuracy of SLM and DMLS in machining internally cooled cutting tool with a special focus on geometrical dimensions such as hole diameter. The surface roughness produced by the two processes are measured with contact perthometer. To achieve the objectives, geometrical dimensions of identical tool holders for internally cooled cutting tools fabricated by SLM and DMLS have been determined by using digital vernier calliper and various magnification of a portable microscope. In the current study, comparing internally cooled cutting tools made of SLM and DMLS showed that generally the higher degree of accuracy could be obtained with DMLS process. However, the observed differences in surface roughness between SLM and DMLS in this study were not significant. The most obvious finding to emerge from this study is that the additive manufacturing processes selected for fabricating the tool holders for internally cooled cutting tool in this research are capable of producing the desired internal channel shape of internally cooled cutting tool.

Tool wear is a major aspect in metal cutting, especially during steel machining. This studies the capability of 1 mm thick uncoated tungsten carbide insert during the turning of AISI 1017 mild steel. The reduction of insert thickness will lead to a more economical and efficient use of material and energy during fabrication, operation, and disposal of the cutting insert. Axial machining trials have been performed using the finishing cutting conditions. Tool flank wear and workpiece surface roughness were analysed using an optical microscope and contact perthometer device, respectively. The data of flank wear and surface roughness achieved were used to analyse the capability of replacing 4 mm thick cutting inserts with 1 mm thick cutting inserts. The results showed that the flank wear and the surface roughness of conventional inserts performed better as compared to the 1 mm thick insert with a significant difference of 5.74 % and 1.57 %. Thus, the experimental study shows that the 1 mm thick insert performed as good as a conventional cutting insert in terms of tool life and surface roughness quality.

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In the last decades machining methods have witnessed an advancement in both cutting tools’ geometry and hard coatings, sometimes in combination with Ti-based coating. In the present study, the machining performance of adhesion resistant Ti-based coating materials with modified cutting insert on tool wear was investigated in turning AISI 1017 carbon steel. TiB2 and TiN hard coatings with similar layer thickness produced by physical vapor deposition (PVD) technique were considered as coating film for 1 mm thick tungsten carbide with Co binder cutting tools. The machining performance was evaluated mainly by surface roughness, cutting temperature and correlated in terms of tool wear. Through a set of experiments, modified cutting insert coated with TiB2 exhibited about 24-33% improvement in tool wear compared to TiN coated insert. The results from this study show that TiB2 coating can be used as coating material for cutting tool but further research on tribology and sustainability along with cutting dynamics study are prerequisites for commercial application of this coating material in the mainstream.