IMPACT OF MATERIAL AND DIMENSIONS OF PRODUCT UPON PARAMETERS OF WAVE DEFORMATION STRENGTHENING

Previously it was defined that geometrical dimensions of material worked have a significant impact upon the process of wave deformation strengthening, as at equal volumes of strengthened samples and processing modes there are observed different cards of micro-hardness in surface layers. In the paper there are shown investigations of the impact of dimensions of samples made of different material kinds (steel 45, titanium VT 1-0, bronze BRAZh 9-4, aluminum alloy B-95) upon wave deformation strengthening parameters). The investigations mentioned were carried out for the first time on a test desk specially developed. Strengthening effectiveness was estimated according to micro-hardness distribution in a surface layer. The analysis of the results obtained allowed defining that in chosen modes of WDS takes place strengthening not only a face surface but a back one of the sample at that in the core of the sample an initial hardness of material is kept. The investigations carried out allowed defining the fact that at the increase of material thickness from 10 to 20 mm resulted in the growth of degree (ΔHμ) and depth (hμ) of strengthening at WDS of samples of steel 45 - by 24 and 32%, samples of bronze BRAZh 9-4 – by 22 and 21%, samples of titanium VT 1-0 – by 24 and 32%, samples of aluminum alloy B-95 – by 40 and 62%. The samples length increase from 50 to 100 mm is accompanied by the decrease of ΔHμ and hμ at strengthening: steel 45 – by 36 and 70%, bronze BRAZh 9-4 – by 27 and 43%, titanium VT 1-0 – by 24 and 32%, aluminum alloy B-95 – by 40 and 62%.

MATERIAL MODELS AT RESEARCH OF WAVE DEFORMATION STRENGTHENING THROUGH FINITE ELEMENT METHOD

The problem of necessity in the development of loading environment models (materials processed) which has great importance at the finite element simulation of basic processes (technologies) is considered. As a rule, material model programs embedded into CAE cannot be used completely in the computations because of their limited set of physical-mechanical properties, most often insufficient for the adequate simulation of the process under investigation. By the example of the technology of wave deformation strengthening taking into account its peculiarities in the paper for the first time there are developed material models: steel45, BrAZh9-4; VT1-0; B-95 and the estimation of their adequacy is carried out. The creation of each model of material is a unique process and implies not only the pattern completion with data from reference books, but also with data obtained as a result of the fulfillment of corresponding experimental investigations of properties peculiar to material under working. As a result there are developed adequate models of materials having an admissible error (not exceeding 7.4%) for micro-hardness and depth of surface layer strengthening that allows recommending their use at the investigation of wave deformation strengthening through a finite element method.

Technological capabilities for control of effective cold working depth of surface layer by wave strain hardening

The parameters of wave deformation are described. The results of studies of the effect of the diameter of the instrument used for wave deformation of flat surfaces on the quality parameters of the hardened surface layer are presented. A significant increase in depth and degree of hardening after processing has been established, and the parameters of the tool and the technology of its application to obtain the most effective results have been determined.