Single grain grinding: a novel approach to model the interactions at the grain/bond interface during grinding

Abstract

The influence of the bond on grinding processes remains one uncertainty in the investigation of grinding tool behavior. Among others, this is due to the lack of knowledge about the interactions between the grain/bond interface and the grinding process loads. Understanding these interactions allows for further process development by adjusting the bond to the grinding application. The interactions at the grain/bond interface during grinding depend on the single grain thermomechanical loads as well as the tool properties. This paper presents an approach to provide the boundary conditions which are needed to model the interactions at the grain/bond interface. The machining of tungsten carbide with a bronze-bonded diamond tool is considered as use case. For this purpose, a novel kind of tool extracted from the grinding layer that serves to quantify the loads affecting the active grains and consequently their grain/bond interfaces during grinding is developed. The results of different grain orientations are plotted in a so-called Acu diagram, which gives an overview of the mechanical loads for different grain orientations and chip thickness values, as they occur during grinding due to the stochastic orientation and distribution of the abrasive grains in the grinding tool. It is shown that depending on the engagement conditions, the single grain-cutting force can reach up to 300 N by chip thickness values of 20 μm, which implies different wear behavior of the active grains.