In the given work we present the results of experimental estimation of chip shrinkage under turning with straight and radius cutters for two schemes of cutting: "direct" and "reverse". Ratios of thickening, broadening and longitudinal shrinkage of the chip were established as shrinkage parameters. The given paper presents the graphic charts showing dependences of shrinkage upon cutting depth, supply and cutting edge inclination which indicate the deformations taking place in the cutting area when cutting with cup-tip cutters. The authors show the significant difference in the character and degree of chip shrinkage when working according to various schemes of cutting.

The paper considers the method of determining the components of the cutting force under cutting completed with a radius cutter. The authors provide the design of the experimental study. The authors provide the data on the cutting force change in the process of turning with a radius cutter according to the cutting edge inclination, cutting depth and supply obtained experimentally and calculated analytically. The paper also provides the results of experimental work approximation and theoretical error checking related to experimental data.

The article is presented results of a study of the process for a dry friction metalpolymer couple on scheme disc-finger. Track membrane from polyethylene terephthalate was a research material. Membrane had pores with 0.4 and 0.8 µm diameters. The effect of the sliding velocity for membranes with pores of 0.8 microns was determined. Research was shown that increasing pore's diameter caused a reduction of the friction coefficient and downturn its magnitude vibrations. The study showed that track membrane have adequate resistance to wear and can be successfully used in surgical procedures in the layers of the cornea.

The effects of the low-temperature plasma exposure, gg irradiation, and combined γ irradiation and plasma exposure on the structure and surface properties of thin films based on polylactic acid (PLA) are studied. Films are prepared by the solvent casting method. It is shown that films based on polylactic acid have topographically different sides: a smoother inner side and an embossed outer one. PLA films have properties close to hydrophobic ones, with a contact angle in the range of 70°–73° regardless of the surface side. They belong to weakly polar materials. The combined effect of plasma and gg irradiation slightly changes the surface topography. The effect of low-temperature plasma on the surface of the films leads to a decrease in the contact angle by 13°–55° (9–11%) and an increase in the surface energy due to the polar component. The results of in vivo experiments on rabbits are presented. Biomicroscopy, optical coherence tomography, and morphological and electron microscopic examination of the cornea after implantation of the initial and radiation- and plasma-treated films show that implantation of the films in the anterior chamber is not accompanied by a pronounced inflammatory reaction and increased intraocular pressure, while maintaining the morphological structure of the cornea almost unchanged.

The roughness of a milled surface is investigated for AISI 321 austenitic stainless steel with different structure and mechanical properties. The grain size is modified by familiar methods of...