This page has only limited features, please log in for full access.
Based on the classical theory of heat conduction and thermoplastic mechanics, the three-dimensional heat transfer and thermal stress models of high-velocity oxygen fuel WC–10Co4Cr coating under the action of a moving heat source during grinding were developed. Considering temperature-dependent material properties, the transient temperature field and the thermal stress field generated in workpiece were simulated by a finite element method (FEM). As both the thermal conductivity and the specific heat capacity of WC–10Co4Cr are larger than 300 M, temperature rise mainly occurred in the coating. The rise in grinding temperature was discontinuous along the depth of the workpiece, and the temperature gradient at the coating–substrate interface was found to be the largest. Due to the large difference in thermal expansion coefficient between coating and substrate material, considerable thermal stress was generated at the bonding surface. Grinding temperature and thermal stresses at the coating–substrate interface started to increase with the decrease in coating thickness. Grinding surface temperatures were measured experimentally for different coating thicknesses, and simulation results were compared with the obtained experimental values. It was found that FEM results were well consistent with experimental observations.
Jun Yi; Zhaohui Deng; Wei Zhou; Shujian Li. Numerical Modeling of Transient Temperature and Stress in WC–10Co4Cr Coating During High-Speed Grinding. International Journal of Precision Engineering and Manufacturing 2019, 21, 585 -598.
AMA StyleJun Yi, Zhaohui Deng, Wei Zhou, Shujian Li. Numerical Modeling of Transient Temperature and Stress in WC–10Co4Cr Coating During High-Speed Grinding. International Journal of Precision Engineering and Manufacturing. 2019; 21 (4):585-598.
Chicago/Turabian StyleJun Yi; Zhaohui Deng; Wei Zhou; Shujian Li. 2019. "Numerical Modeling of Transient Temperature and Stress in WC–10Co4Cr Coating During High-Speed Grinding." International Journal of Precision Engineering and Manufacturing 21, no. 4: 585-598.
This paper proposes intermittent feed high-speed grinding, which shows considerable advantages in terms of reducing grinding temperature, relieving grinding wheel blockage and improving workpiece surface integrity. In this grinding, the continuous feed mode of the workpiece is changed into the normal feed + fast retreat reciprocating feed mode by a fast linear feed worktable. By reasonably setting the normal feed distance of single grinding, the action time of the grinding wheel and workpiece is reduced, so that the grinding heat transfer process does not reach a stable state, reducing the grinding temperature during single grinding. Besides this, the surface temperature is cooled to nearly room temperature and the grinding wheel is flushed by the timely retreating of the grinding wheel to allow the grinding fluid to enter the grinding zone fully, which greatly reduces the phenomenon of heat accumulation and grinding wheel loading. An intermittent feed high-speed grinding experiment on Ti-6Al-4V (TC4) titanium alloy was systematically carried out, and the influence of the grinding parameters on grinding force and grinding temperature was deeply analyzed. The instantaneous grinding temperature field and thermal stress field of TC4 titanium alloy in intermittent feed high-speed grinding were constructed with the finite element method. The surface morphology of the grinding wheel and TC4 titanium alloy specimens after intermittent feed grinding were analyzed and were compared with those after traditional continuous grinding. It was found that the curves of the grinding force and temperature varied with time in the process of machining, consisting of many “pulse” peaks. Under the same grinding parameters, the magnitude of the grinding force is the same as that of continuous grinding. In a certain range, the grinding temperature is greatly affected by the single feed distance and the interval time. The numerical simulation results are in good agreement with the experimental results, and the error is controlled within 12%. Compared with traditional high-speed grinding, under the same process parameters, the grinding temperature is greatly reduced, the surface integrity of the workpiece is better, and the clogging of the grinding wheel is greatly reduced.
Jun Yi; Wei Zhou; Zhaohui Deng. Experimental Study and Numerical Simulation of the Intermittent Feed High-Speed Grinding of TC4 Titanium Alloy. Metals 2019, 9, 802 .
AMA StyleJun Yi, Wei Zhou, Zhaohui Deng. Experimental Study and Numerical Simulation of the Intermittent Feed High-Speed Grinding of TC4 Titanium Alloy. Metals. 2019; 9 (7):802.
Chicago/Turabian StyleJun Yi; Wei Zhou; Zhaohui Deng. 2019. "Experimental Study and Numerical Simulation of the Intermittent Feed High-Speed Grinding of TC4 Titanium Alloy." Metals 9, no. 7: 802.