Modeling and research of temperature distribution in surface layer of titanium alloy workpiece during AEDG and conventional grinding

M Gołąbczak,R Święcik,A Gołąbczak,A Konstantynowicz

doi:10.1007/s00161-016-0509-y

M Gołąbczak, R Święcik + Show 2 more

Open Access

https://doi.org/10.1007/s00161-016-0509-y

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Abstract

Titanium and its alloys are widely recognized as the hardly machinable materials, especially due to their relatively high hardness, low thermal conductivity and possible subcritical superplasticity. Then, a thorough control of the machining process parameters shall be maintained. In this paper, we have concentrated on the grinding of the Ti6Al4V titanium alloy using cBN (boron nitride) grinding wheel combined with the AEDG (abrasive electrodischarge grinding) process. The mathematical model we have dealt with has been based mainly on Jaeger model of the heat taking over between sliding bodies with substantial upgrades related to: estimation of the frictional heat generating based on friction forces distribution, spatial, not only planar, shape of the contact area, generated heat partition between different parties of the grinding process, heat transfer in the multilayered environment. The experimental verification of the theoretical predictions has been carried out. Fundamental difficulty in such a research is placing temperature probes sufficiently close to the ground surface with possibly low space devoted for probes due to the temperature field deformation with relation to the real conditions of grinding. The temperature field in the machined workpiece has been investigated using electronic data logging and DSP methods. Obtained results exhibit clearly that distribution of heat generation in the contact zone could be of the relatively complicated shape due to the external cooling and the very specific heat transfer and accumulation in the titanium workpiece surface layer.

Highlights

Jaeger model basicsJaeger model is based on the slightly idealized considerations of the heat transfer mechanism between sliding body and infinite semi-surface [6]
Estimation of the frictional heat generating based on friction forces distribution, spatial, planar, shape of the contact area, generated heat partition between different parties of the grinding process, heat transfer in the multilayered environment
Some results have been presented related to mathematical modeling and experimental researches of the temperature distribution in the surface layer during the conventional and electroerosive grinding of the titanium alloy Ti6A14V with using cooling dielectric liquid

Summary

Jaeger model basics

Jaeger model is based on the slightly idealized considerations of the heat transfer mechanism between sliding body and infinite semi-surface [6] Idealized, this model proved to be reliable in the strict technical conditions related with the grinding process [7,8] and provide the great help in better understanding of the temperature distribution rules in the surface layer. We have assumed grinding effective power and shape of the heat distribution curve as the estimated parameters, which have resulted in the very effective fitting of the Jaeger model to our specific process conditions [3,4,7]. The spatial heat distribution along the contact zone—function f (l), acts in our work as the specific model parameter allowing “bending” temperature curve independently of the effective grinding power supplied by abrasion and AEDG processes into the contact zone

Classical dry grinding

Conclusions