Model-based analysis of the effects of bonding properties and thermomechanical influences on the grain–bond interface during grinding with sintered metal-bonded tools.

CBN is suitable for grinding hardened steels, with a portion of the heat being conducted through the sintered metal–bronze bond into the grinding spindle. This results in overlapping mechanical and thermal loads at the grain–bond interface. Previous work has shown plastomechanical deformations that alter the grain orientation and thus the tool topography. Such effects have so far been neglected in process design; models that reliably represent the deformation mechanisms at the interface and their impact on wear, forces, and resulting surface quality are lacking. For industry, this translates into uncertain predictions, unnecessary scrap, and suboptimal tool life.

Objectives

The aim of the project is to understand and predict the elastoplastic deformations of the sintered metal bond on CBN grains under combined mechanical and thermal loads. To this end, single-grain scratch tools with bronze bonds and varying bonding properties are manufactured and characterized. A finite element model represents the deformation mechanisms at the grain–bond interface for variable grain orientation and loading. Force and temperature measurements from scratch tests are used for calibration and validation. An empirical process model is derived from these data, integrated into the kinematic simulation IFW CutS, and validated in grinding trials—with the goal of reliably predicting surface quality, forces, and tool behavior.

Benefits

• Reliable surface and force predictions – reduced scrap
• More robust process design – extended tool life

Approach

In the DFG-funded project, we are developing a model- and data-driven understanding of the grain–bond interface. The grinding process is abstracted into recurring micro-interactions (single-grain scratches, local heat/force clusters), with forces and temperatures being recorded. This yields a validated process model, which is integrated into IFW CutS. The predictions are verified in grinding trials and validated across a range of process parameters.

Are you also interested in a cooperation project?

Contact Michael Wulf via email at wulf_m@ifw.uni-hannover.de or by phone at +49 511 762 18354.