Titanium alloys and stainless steels are hard-to-machine of all the machining types. Cutting edge state of turning tool after machining titanium and high-strength aluminium alloys and corrosion-resistant high-alloy steel has been studied. Cutting forces and chip contact arears with the rake surface of cutter has been measured. The relationship of cutting forces and residual stresses are shown. Cutting forces and residual stresses vs value of cutting tool rake angle relation were obtained. Measurements of residual stresses were performed by x-ray diffraction.

The article describes the results of experimental studies on the effects of variation type for variable teeth pitches on low-rigidity workpiece chatter suppression efficiency in a feed direction and in a direction of the normal to the machined surface. Mill operation performance was identified by comparing the amplitudes of dominant chatter harmonics using constant and variable teeth pitches. The following variable pitch formation variants were studied: alternative, linear rising, and linear rising falling. The angle difference of adjacent teeth pitches ranged from 0 to 10°, from 5 to 8° and from 5 to 10° with interval of 1°. The experiments showed that for all variants, machining dynamics performance resulted from the difference of adjacent pitches corresponding to a half the chatter wavelength along the cutting surface. The alternative nature of a variable teeth pitch is most efficient as it almost completely suppresses the chatters. Theoretical explanations of the results are presented

This article discusses the possibility of suppressing vibrations when drilling holes with spiral drills. This article presents two methods of suppressing vibrations: modal analysis and modulation of cutting speed (changes in spindle speed - Spindle Speed Variation - SSV). There is a description of the considered methods with an indication of their advantages and disadvantages. The article also points out to experimental data that characterize the possibility of suppressing vibrations when drilling holes and a comparative analysis of various methods of suppressing vibrations when machining holes in samples of their structural steel. There is an assessment of the possibility of joint application of modal analysis methods and modulation of cutting speed during high-performance drilling.

Titanium alloys are hard to machine by all types of cutting. The cutting data influence on the output parameters of the turning process after the VT20 titanium alloy machining has been studied. The turning cutters with carbide inserts were used that enable cutting in a forward and reverse direction. Cutting forces, vibration, surface roughness and residual stresses were measured. Measurements of residual stresses were performed by x-ray diffraction. The relationship of output parameters and the cutting data are shown.

One of the new but understudied self-oscillation elimination methods applied in metal cutting involves creation of an extra tangential oscillating circuit adjusted to resonance with the main normal circuit in the cutting zone. To assess the efficiency of the method, spring tool and driving dogs were developed. They were used in axial turning of non-rigid shafts. In comparison with standard tools fastened in the center, spring tools decrease the amplitude of self-oscillations by a mean of 90 %.