The ability to predict a grinding force is important to control,monitor,and optimize the grinding process.Few theoretical models were developed to predict grinding forces when a structured wheel was used in a grinding...The ability to predict a grinding force is important to control,monitor,and optimize the grinding process.Few theoretical models were developed to predict grinding forces when a structured wheel was used in a grinding process.This paper aimed to establish a single-grit cutting force model to predict the ploughing,friction and cutting forces in a grinding process.It took into the consideration of actual topography of the grinding wheel,and a theoretical grinding force model for grinding hardened AISI 52100 by the wheel with orderly-micro-grooves was proposed.The model was innovative in the sense that it represented the random thickness of undeformed chips by a probabilistic expression,and it reflected the microstructure characteristics of the structured wheel explicitly.Note that the microstructure depended on the randomness of the protruding heights and distribution density of the grits over the wheel.The proposed force prediction model was validated by surface grinding experiments,and the results showed(1)a good agreement of the predicted and measured forces and(2)a good agreement of the changes of the grinding forces along with the changes of grinding parameters in the prediction model and experiments.This research proposed a theoretical grinding force model of an electroplated grinding wheel with orderly-micro-grooves which is accurate,reliable and effective in predicting grinding forces.展开更多
To improve the bonding strength between the nickel bond and the hub of the electroplated diamond grinding wheel,a hybrid technique was proposed to combine laser prequenching steel substrate and post-electroplating nic...To improve the bonding strength between the nickel bond and the hub of the electroplated diamond grinding wheel,a hybrid technique was proposed to combine laser prequenching steel substrate and post-electroplating nickel.To validate the effectiveness of the proposed technique,AISI 1045 substrate was nickel-coated.The bonding properties between the electroplated nickel coating and substrate with or without laser-discrete-quenching were discussed comparatively by scratch,indentation,and thermal shock tests.The results show that the prequenching treatment leads to phase transformation of AISI 1045 microstructure from the mixed pearlite and ferrite phases into the martensitic phase.Since the martensitic phase is characterized as a high corrosion resistance,the interface of substrate/coating is smooth and flat in the prequenched zone,and the coating is bonded well with the steel substrate.In contrast to the steel substrate without pre-quenching treatment,the proposed technique significantly enhanced the bonding strengths of the electroplated nickel-coating.On one hand,the average hardness of electroplated nickel-coating on the laser pre-quenched zone is increased by 18.7%,and the scratch depth with the same load become narrower and shallower.On the other hand,the coefficient of friction(CoF)and the vibration amplitude are reduced,and the coating is bonded effectively with the substrate to inhibit the crack initialization at the interface.This prevents effectively the coating from peeling off and improves significantly the thermal shock resistance property.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52275405,52275311,51875050)Hunan Provincial Key Research and Development Program(Grant No.2021GK2021).
文摘The ability to predict a grinding force is important to control,monitor,and optimize the grinding process.Few theoretical models were developed to predict grinding forces when a structured wheel was used in a grinding process.This paper aimed to establish a single-grit cutting force model to predict the ploughing,friction and cutting forces in a grinding process.It took into the consideration of actual topography of the grinding wheel,and a theoretical grinding force model for grinding hardened AISI 52100 by the wheel with orderly-micro-grooves was proposed.The model was innovative in the sense that it represented the random thickness of undeformed chips by a probabilistic expression,and it reflected the microstructure characteristics of the structured wheel explicitly.Note that the microstructure depended on the randomness of the protruding heights and distribution density of the grits over the wheel.The proposed force prediction model was validated by surface grinding experiments,and the results showed(1)a good agreement of the predicted and measured forces and(2)a good agreement of the changes of the grinding forces along with the changes of grinding parameters in the prediction model and experiments.This research proposed a theoretical grinding force model of an electroplated grinding wheel with orderly-micro-grooves which is accurate,reliable and effective in predicting grinding forces.
基金the National Natural Science Foundation of China(No.51875050)Hunan Provincial Natural Science Foundation of China(No.2019JJ40293)Changsha City Planned Science and Technology Project(No.kq1907088)。
文摘To improve the bonding strength between the nickel bond and the hub of the electroplated diamond grinding wheel,a hybrid technique was proposed to combine laser prequenching steel substrate and post-electroplating nickel.To validate the effectiveness of the proposed technique,AISI 1045 substrate was nickel-coated.The bonding properties between the electroplated nickel coating and substrate with or without laser-discrete-quenching were discussed comparatively by scratch,indentation,and thermal shock tests.The results show that the prequenching treatment leads to phase transformation of AISI 1045 microstructure from the mixed pearlite and ferrite phases into the martensitic phase.Since the martensitic phase is characterized as a high corrosion resistance,the interface of substrate/coating is smooth and flat in the prequenched zone,and the coating is bonded well with the steel substrate.In contrast to the steel substrate without pre-quenching treatment,the proposed technique significantly enhanced the bonding strengths of the electroplated nickel-coating.On one hand,the average hardness of electroplated nickel-coating on the laser pre-quenched zone is increased by 18.7%,and the scratch depth with the same load become narrower and shallower.On the other hand,the coefficient of friction(CoF)and the vibration amplitude are reduced,and the coating is bonded effectively with the substrate to inhibit the crack initialization at the interface.This prevents effectively the coating from peeling off and improves significantly the thermal shock resistance property.