B-Area: Experimental and numerical analyses of the heat input due to machining concerning work piece geometry and microstructure

Person in Charge: Dipl.-Ing. Jürgen Michna ; Dipl.-Ing. Patrick Bollig

Motivation und aims:
The surface states and thus the functionality of machined work pieces are influenced strongly by parameters of the process and the cutting tool. Depending on these variables different mechanical and thermal loads lead to characteristics of components. Undefined distortion of work pieces and phase transformations in surface layers can be results of the machining process.
The project therefore has the aim to examine, analyze, model and control machining induced phase transformations and work piece distortions.

Research

Results

2D-FE cutting simulation with detailed modeling of friction, heat transfer and phase transformations for the steel 42CrMo4 (AISI4140)
Turning and drilling experiments with measurement of temperatures and forces
Abstract modeling of the drilling process (3D-FE model)
Simulation of phase transformations and work piece distortions
Defining strategies of compensation

Thermal image of drilling experiment

2D-FE model shows good agreement of calculated temperatures and forces in relation to the measured results of the turning experiments
Austenization implemented in cutting simulation
Friction coefficient decreases with increasing sliding speed and approaches towards a maximum at higher temperatures