Surface Characterization And Grinding Performance Of Monolayer Brazed CBN Wheel

The monolayer brazed CBN wheel with defined grain distribution has a wide application prospect in grinding difficult-to-cut materials in aviation and aerospace industry due to its excellent grinding performance.Previous research work has discovered that the undeformed chip thickness per grain has a great impact on grinding force,grinding temperature,wheel life,surface integrity and so on.However,the above-mentioned research work usually assumed that the undeformed chip thickness per grain was equal,so it was difficult to predict grinding result accurately.This is due to the fact that the undeformed chip thickness of different grains is different due to the difference between morphology and height of grains.Therefore,in order to provide a scientific basis and basic data for accurate prediction of grinding results,the author establishes a distribution model of undeformed chip thickness per grain on the basis of the characterization of the abrasive wheel surface status and the analysis of the influence of undeformed chip thickness distribution on grinding process.The main research work and results are as follows:(1)The replica method has been adopted to characterize the surface topography of the monolayer brazed CBN wheel with defined grain distribution.Meanwhile,a 50×1047 matrix was used to describe the height and position of each grain on the wheel surface.The formula to calculate the undeformed chip thickness per grain was derived,through which the distribution of undeformed chip thickness(including the mean value and the standard deviation)was calculated based on wheel topography.(2)A monolayer brazed CBN wheel with defined grain distribution was fabricated,and the grinding experiment of nickel-based superalloy GH4169 was conducted to study the wheel wear.The evolution of wheel surface status was clarified and the influence of wheel wear and grinding parameters on the distribution of undeformed chip thickness was discovered in order to provide theoretical basis and basic data for optimizing grinding parameters to control the distribution of undeformed chip thickness in grinding.(3)A grinding experiment was conducted to reveal the influence of surface status on grinding force,specific grinding energy,grinding temperature and surface roughness.The relationship between the distribution of undeformed chip thickness and the grinding process parameters and the grinding results as well was established,with which the results error of the model could be controlled within10%.