Improvement of grinding technology with vortex cooling of steels that are liable to crack propagation

Abstract

Complexity of grinding process and phenomena entailing it not always allow reaching required technological results, especially while machining surfaces of parts made of tough-to-machine steels, which are liable to crack propagation. Cracks can occur in these parts during grinding due to considerable temperature difference along the section, which can cause formation of high temporary internal tensile stress. Application of cooled air in grinding process exerts considerable influence over temperature decrease in cutting area. In addition, it depends not only on heat exchange, but also on properties of cold air flow. The greatest effect of temperature decrease can be reached by injection of cold air flow in cutting area with implementation of vortex effect, which occurs in swirl flow of compressed air originating in vortex tube. The study of heat generation during machining by tools with discontinuous cutting surface and vortex air cooling was carried out. Obtained thermophysical parameters of vortex air cooling (increase in speed of stream flowing, expansion degree, share of cold stream and decrease in humidity of air stream) allow reducing heat density due to growth of cooling effect in grinding zone. On the base of experimental studies we developed recommendations for choice of optimal grinding modes by tool with discontinuous cutting surface and vortex air cooling of flat parts made of steels being liable to cracking.

Kinematic Error Modeling of Delta 3D Printer

“…With the help of additive technologies, it is possible to multiply the coefficient of material utilization, because instead of cutting the material, it grows. Only subsequent finishing is required to reduce the surface roughness [1][2][3][4]. Also, the development of additive technologies contributes to the transition to digital manufacturing.…”

Grinding of High-Strength Materials

“…The properties of surface zone are formed before grinding, so the surfaces with the same roughness can have different operational properties. Consequently, physical and mechanical properties of the machined surface depend on the whole complex of fulfilled technological operations [11,13,14].…”

Technological Forecasting of Deformations in Flat Parts

“…The strain state in every point of a part is characterized by the relative linear deformations εx, εy, εz, while the stress state is determined by σx, σy, σz (Ivanova, 2016;2018;2019;Ivanova et al 2019;Zakharov et al 2016;Tyutha et al 2016;Zitnansky et al 2013;Davim 2011;Grote 2011;Fritz & Schulze 2010;Klocke & Konig 2013, Klocke & Kuchle 2011Groover 2010;Boge 2011;Huo & Cheng 2013;Jackson & Hitchiner 2012;Rowe 2010;Toenshoff & Denkena 2013). Let us analyze two cases of part installation and fastening.…”