ON THE ISSUE OF THE CUTTING TOOL MATERIAL SELECTING FOR THERMOPLASTIC POLYMERS TURNING

The article is devoted to solving the issue of rational choice of cutting tool material used for turning thermoplastic materials. For the research, modern thermoplastic polymer materials caprolon B and fluoroplastic-4 were selected, which are intended for the production of a wide range of parts in various industries. For turning thermoplastics, prefabricated cutters were used, which were equipped with replaceable multifaceted inserts made of different tool materials, namely: one made of tungsten-cobalt alloy VK8, the other made of ceramic material – tungsten-free hard alloy KNT16. A study was carried out using an electron microscope of the structure of chips obtained by turning caprolon and fluoroplastic workpieces with different tool materials. To control the values of the tangential component of the cutting force during turning of thermoplastic workpieces, a beam force sensor is used, mounted under the cutter, with the numerical values of the cutting force component displayed on the liquid crystal display screen. An experimental study was carried out on the roughness of the machined surface of thermoplastic polymer materials after turning with cutting tools made of various materials. It has been established experimentally that the option of turning workpieces with a cutting tool made of KNT16 cermet is more preferable compared to the options of turning with a tool made of VK8 alloy. This is evidenced by more uniform deviation profiles of the depressions and protrusions of the surface profile and indicators of the values of the studied roughness parameters.