Influence investigation of technological conditions of 3D-printing on antiadhesion properties of master-model surfaces

It is shown that one of the promising methods to prepare a master-model for the casting production of engineering industry products is FDM 3D-printing. The influence of technological conditions of 3D-printing on antiadhesion properties of surfaces has been studied. By experiments it was found out that for 3D-printing of master-models it was necessary to have conditions in which the parameter of filling percent was more than 60%. Recommendations for the use of 3D-printing methods for production of casting molds are given.

Estimation of stressed-deformed state of polymer composite material with hybrid matrix

Properties of polymer composite material consisting of carbon fabric and two matrix types (epoxy and organic-silicon) have been studied. The main purpose of the organic-silicon matrix is to relax stresses arising in carbon-filled plastic components under loads and to decelerate (or stop) crack growth. The structure of the composite material was determined by using a tomography. On the basis of the structure, a finite-element model was developed and a calculation of the stressed-deformed state depending on elastic characteristics of the matrix was performed. A safety factor calculation was made. It was found out that the addition of organic-silicon material in the composite composition made possible to decrease stress values in the crack tip that considerably increased the service life of such materials.

Effect determination of operating environments on growth of subfilm corrosion of machine parts with dispersion-filled polymer coatings

Detection methods of subfilm corrosion as well as the effect of operating environments on the corrosion growth rate have been examined. The study results of the effect of operating environments on parts with organosilicon polymer coatings modified with various dispersed fillers are presented. It is shown that the addition of mica into the composition of an organosilicon coating make possible to have a protective anticorrosion coating with good adhesion to the metal surface. The effect of operating environments on wettability of the polymer coating surface is described.

Modern liquid embolizing agents based on polymers: composition, properties and applications (review)

Analysis of published information on polymer-based liquid embolizing agents is carried out in this review. The registered and used brands are described: Onyx™, PHIL™ and Squid, as well as less well-known Easyx™ and Menox™. Data on their composition, properties and application are given. The advantages and the disadvantages of the described embolizing agents are discussed.

Chemically-modified polysulfones and their properties

The review of works including works by the authors, concerning aromatic polysulfones chemically-modified on the main macrochain is presented. Methods of synthesis of copolymers and block-copolymers with increased heat-resistance by the use of new original compounds are described. Application availability of the modified polysulfones for production of heat-resistant filled composite materials is demonstrated.

Assessment of stability of varnish-and-paint coatings on polymer composite material components to ultraviolet radiation effect

The results of accelerated climatic test of protective and decorative properties of varnish-and-paint coatings deposited on polymer composite material samples by different technologies to the ultraviolet radiation effect (GOST 9.401—2018) are presented. Assessment of the protective and decorative properties of varnish-and-paint coatings was carried out according to the procedures in GOST 9.407—2015, measurement of coating adhesion was performed according to the procedures in GOST 31149—2014 (ISO 2409:2013).

Comparison of national and foreign normative documents on radiographic control. Advantages and disadvantages.

Proceeding from the requirements regulated by the ISO 17636-1 and state standard specification 7512, state standard specification 20466 standards features of processes of forming of radiation images and their transformation to optical patterns are considered. The assessment of quality of optical patterns and productivity of radiographic control on different systems of standards is carried out. It is shown, from the point of view of, achievable sensitivity of control that transition from state standard specification to ISO will not lead to control deterioration, however will increase control productivity in 1,5÷2,0 time.

RHEOLOGICAL BEHAVIOR OF POWDER-POLYMER MIXTURES AND MODEL DESCRIPTION OF FEEDSTOCK VISCOSITY FOR NUMERICAL SIMULATION OF INJECTION MOLDING PROCESS

The rheological behavior of the powder-polymer composition prepared for the application in the powder injection molding (PIM) technology has been studied. A review of models used to describe the rheological behavior of powder slips is presented. A viscosity study of MIM-4140 feedstock with a wax-polyolefin binder was carried out on a capillary rheometer with different capillary diameters. Empirical coefficients of viscosity models were determined. Verification of calculated viscosity values and experimental data for the studied feedstock is presented.

Resistance determination of joints of plastic components, made by additive technologies, to effect of negative temperatures

The effect of negative temperatures on strength characteristics of plastic component joints (hot gas welding, gluing, 3D-welding) made with the use of additive technologies has been examined. It has been found out that 3D-wlding allows one to produce joints with the highest strength properties. It was shown that low temperature values (–30 °С) did not have the negative influence on strength properties of ABS-plastic joints but even increased them as compared with analogues samples tested at the room temperature.