Technology of sliding friction surface machining based on hard wear-resistant coating use taking into account technological inheritance impact

The matters of technological support of wear-resistance for sliding friction surfaces are considered. The results of experimental theoretical investigations of modes impact of preliminary machining, coating application and sliding friction surfaces finishing upon their quality parameters are shown.

Analysis of inheritance mechanisms in animate nature and engineering

The evolution of ideas on inheritance is analyzed and basic types of inheritance in animate nature are presented. Reasoning from the analysis of terms adopted in genetics and engineering technique there is carried out the analysis of inheritance mechanisms at machining and machinery operation. There is shown the evolution of ideas on hereditary information: first the part manufactured the accuracy dimensions of which were “copied” (inherited) in the course of engineering procedure; further – a thin surface layer formed during the engineering process and within the frames of the scientific investigation carried out – material of the deformation source where a plastic metal flow takes place. An analysis is carried out and the directions of the development of scientific investigations in the field of technological inheritance are presented.

Study of Surface Layer Hardening after Treatment Complex Tool

The results of experimental studies of the thin surface layer of samples made of steel 45 after treatment with surface plastic deformation (SPD) multiradius roller (MR-roller) are presented. On the basis of the apparatus of the mechanics of technological inheritance, taking into account the effect of the solidified body, a model of the process according to the scheme of multiple loading-unloading of metal, taking into account the phenomenology of the SPD process and the properties of the material, is created. Distributions of parameters of the stress-strain state in the deformation centre are obtained, the parameters of roughness and microhardness of the surface layer are investigated.

Technological inheritance in metal forming

Ogorodnikov V., Arkhipova T. Technological inheritance in metal forming. Material working by pressure. 2020. № 1 (50). Р. 28-32. Technological heredity in metal forming processes is accompanied by hardening, the appearance of residual stresses, a deformation gradient, residual plasticity and a number of other factors that determine the operational properties of the product. The influence of most factors of technological heredity on the mechanical properties of the material of products has been studied, however, the plasticity of a pre-deformed workpiece remains insufficiently studied. For a quantitative assessment, a calculation method is proposed, with the help of which it seems possible to determine the plasticity resource of pre-deformed blanks. The developed calculation apparatus is based on a fracture model based on a tensor description of damage accumulation. It allows for the known mechanical characteristics to predict the plasticity characteristics of pre-deformed blanks at any type of stress state. The proposed method assumes the use of plasticity diagrams, which describe the change in ultimate deformation depending on the stress state indicators. Plasticity diagrams are constructed for materials tested under conditions of linear or plane stress states (tension, compression, torsion). The practical significance of the results is evidenced by the assessment of the plasticity of steeply curved elbows obtained by the method of cold plastic deformation according to a combined scheme, including deforming pulling of a pre-willed workpiece. In this case, the workpiece in the form of a pipe was subjected to plastic bending. The proposed method makes it possible to assess the residual plasticity of the finished bend. A satisfactory convergence of the calculated and experimental data has been revealed.

QUALITY CONTROL PROCESS SIMULATION OF PRODUCTS MANUFACTURED TAKING INTO ACCOUNT TECHNOLOGICAL INHERITANCE

There are considered scientific-methodical approaches to the formalization of methods for the formation and choice of efficient technologies ensuring a required quality of products, the decrease of labor intensity, power inputs, material capacity and cost price of their manufacturing for conditions of automated decision-making in integrated CADs. A possibility to form multivariate simulators of engineering processes and separate processing methods is shown for which there are described principles of their structural parametric optimization.

Design guidelines for plastic casting using 3D printing

The main aim of the presented tests was to assess the possibility of using 3D printing and casting material to produce casting molds and prototypes, especially in production of existing models. The analysis was based on the assessment of dimensional accuracy and quality of the surface layer of a finished prototype and the intermediate elements made during the production process. The mold was made using the PolyJet Matrix additive technology, and then a silicone mold was cast which was used to prepare a finished sample for testing in accordance with the design assumptions. Based on the results of metrological measurements, the phenomenon of technological inheritance in terms of error transfer in the foundry industry was evaluated. The measurements obtained suggest that in case of casting process, the hereditary features are transferred from individual casting processes, which is especially prominent in the case of surface texture quality. This confirms the occurrence of the phenomenon of the so-called technological inheritance and the need to analyze it. The results of the tests can be a guide for technologists who design molds, core boxes, and casting models, concerning the corrections (shrinkage) that need to be introduced at the design stage in order to obtain a product (casting) of satisfactory dimensional accuracy and quality of the surface layer. The result can also be useful for casting materials reinforced with glass fiber, carbon fiber, which are common materials in 3D printing and textile industry.