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The author [18] proposed to increase the efficiency and quality holing by drilling process
stabilization when the products of polymeric composite materials are manufactured. Two new PCM drilling
ways to better the hole drilling quality was developed: compensating vibration drilling, air-cooled drilling. It
has been proven that in order to improve the stability of the drilling process and improve the quality of holes
drilling the workpieces of PCM should be imposed on the tool forced vibrations. The authors conclude that
the productivity increase of PCM drilling process and high quality of holes could be achieved by cooling the
cutting zone and the cutting tool applying cooled air of subzero temperatures. The described drilling method
demonstrates much greater drill durability up to 35 – 40% compared to the conventional drills. But these
methods have certain disadvatages: the complexity of the operating unit; the need in additional equipment to
the machine (vibratory mandrel, vortex tube, duster); vibration isolation of other equipment elements;
constant control of the cutting tool balance.
To reduce the separation in the hole entrance, it is recommended to use a drill with a double ground
blades, and to eliminate the usage of cut-proof fiber-drills with sharp edges on the periphery. To avoid
separation it is, sometimes, necessary to apply conductors which are pressed against the surface with a force
sufficient to prevent delamination [16]. But certain difficulties arise when being processed blanks of
heterogeneous materials such as carbon fiber and a titanium alloy. It is obvious, in this case they have to
select the tool suitable for drilling of both types of materials or to process them with two different tools.
It should be noted that for the processing PCM - except milling cutters, drills and cutters - diamond
abrasive tools on galvanic and metal bonds are widely used. This method is greatly suited for contour
processing of the carbon-filled and carbonized plastics to produce the highly precious holes. The use of
diamond tools for PCM processing allows to increase processing performance and tool service life. In the
mentioned works [19], there are considered and designed various abrasive tools used for PCM processing.
The examples of them are the diamond circular drills and the end milling diamond cutter. The design of the
instrument envisages the continuous and intermittent working surface. The continuous working surface of
the tool provides a lower roughness of the machined surface of the PCM, but there is fixed a high
temperature increase in the tool - workpiece contact zone.
The application of the intermittent operating surface allows to reduce heat, improve the sludge
removal, prevent sticking, and increase the tool operability. The design features of the developed diamond
tools are the presence of slots or other structural elements for solid lubrication providing. The advantages of
these types of tools are: high processing efficiency, improved surface finish (Rz = 10…20 microns), reduced
cutting tool wear and increased service life, without defects of various types (burrs, chips, delamination,
etc.). It should be noted that the application of the diamond tool requires special equipment, because the
cutting speed provided by the universal machine is too low if the diamond tool being used. That the abrasive
bit is glazed quickly the important disadvantage is. Let’s consider the possible prospects of using the
combined methods of electro-diamond processing and abrasive tools dressing.
In the domestic and foreign literature the information is virtually absent, or is fragmentary. The
manufacturers are interested in systematized data about PCM machining, since their production requires a
quite different tool design, recommendations about the selection of equipment, cutting tools and optimal
processing conditions. At present, the enterprises specializing in the production of polymeric composite
materials know that such a kind of machining as turning, drilling and milling are made, more often than
before, with the blade tools. The results of scientific, technical and patent research, tell that the technological
level of cutting tools intended for composite materials machining, is not still studied.
Therefore, to optimize the composite materials cutting, to get the maximum performance efficiency
and the desired surface finish the reliable tool is needed. It must meet the specific requirements of the cutting
elements quality, the cutting blade sharpness, modern tool materials of improved physical and mechanical
properties, characterized by high technological parameters.
References:
1.
Лобанов Д.В., Сидоренко С.А., Ющенко Д.А., Большешапова А.В. Анализ и рациональный выбор
полимерных композиционных материалов для изделий по их физико-механическим свойствам / Актуальные
проблемы в машиностроении. Вторая Международная научно-практическая конференция: ежегодный научно-
технический и производственный журнал. – Новосибирск: Изд-во НГТУ, 2015. №2. – С. 206-213.
2.
Ющенко Д.А., Кузнецова Е.М. Перспективы применения полимерных композиционных материа-
лов // Механики XXI веку. Научное периодическое издание по материалам 14-ой Всероссийской научно-
технической конференции с международным участием. № 14. С. 194-198. Братск. 2015.
3.
Сидоренко С.А., Ющенко Д.А., Большешапова А.В. Повышение эффективности получения про-
дукции из композиционных древесных материалов с использованием режущих инструментов // Новые методы