Selection of tools and cutting modes for turning small-sized high-precision parts of micro-wave electronics from beryllium bronze

Abstract

Beryllium bronze has the property of plasticity after heat treatment, which is a decisive factor when choosing the material of conductors in unpressurized coaxial connectors. The presence of burrs on these parts according to technical requirements is not allowed. When turning details of beryllium bronze, difficult to remove burrs appear. The aim of the study is to select a tool and cutting modes for turning small-sized high-precision parts of microwave electronics from beryllium bronze, in which there are no burrs or their size and quantity are minimal. In this study, empirical methods are used in the form of experimental selection of cutting modes and tools for the purpose of combating burrs, and analytical methods in the form of analysis of the character of burrs using the provisions of the theory of metal cutting, analysis of factors affecting the formation of burrs during machining surface parts. On CNC lathes CITIZEN CINCOM studied typical of this type of production tools ten leading manufacturers of precision cutting tools for turning. As a result of the study, it was not possible to completely exclude the appearance of burrs during machining. The smallest size and the number of burrs were obtained when machining with carbide tools manufactured by Swiss companies Fraisa, Utilis, IFANGER, Applitec. TiAlN coating is well suited for beryllium bronze treatment. When turning with a new tool at low speeds, the number of burrs decreases, their character changes, they become small drop-shaped. The processing modes recommended by the tool manufacturer differ from those selected experimentally. For further use of the selection results, it is necessary to create a database of regulatory and reference information on the types of processing for specific materials, tools, machine tools according to the accuracy criteria, taking into account the minimization of the number and size of burrs.