THE CONCEPT OF DESIGNING AN EFFECTIVE COATING FOR A CUTTING TOOL UNDER SPECIFIED OPERATION CONDITIONS BY MODELING ITS RATIONAL STRESSES

PURPOSE. Designing of a rational tool material for the specified operation conditions with the required durability period is difficult due to the lack of appropriate methods. The authors of the article have developed such a method for end milling by carbide-tipped cutters. The value of internal stresses in the cutting wedge of the tool and the distribution nature of these stresses are taken as a parameter having the necessary level of influence on the tool working capacity. Tool coating is accepted as a means influencing the magnitude and nature of stress distribution. The variety of existing architectures of coatings (design, composition, thickness, total thickness and thickness of each layer, etc.) makes it difficult to choose the rational one. Searching for a coating in an experimental approbation is time-consuming and expensive. Therefore, there is the need for computer modeling. METHODS. Using ANSYS software package as a basis for modeling, the stresses is simulated in the cutting wedge of the carbide end mill teeth without coating and with several different coatings. RESULTS AND THEIR DISCUSSION. The most rational tool materials have been experimentally determined by their durability period. They have been compared with the simulated stresses under specified operation conditions. It is found that lower stresses correspond to longer wear resistance periods of the tool. CONCLUSION. By changing the coating architecture in computer simulation of stresses the coatings are selected that provide the required margin of tool wear resistance. They have a 10% excess (40 min) of the specified period of wear resistance. The most technologically convenient coating is chosen from these ones. It is applied to a hard alloy tool tested in real operation conditions. The specified period of wear resistance has exceeded by 8-15%. It is accepted as valid.

cutting tool, cutting process, wear resistance period, coatings, stresses, simulation

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