machiningphys

I am currently researching the field of machining physics, to get some understanding of how the temperature in a machining system can change as machining takes place. This is an extremely complex system. There are 3 components to consider in dry orthogonal machining, these are the 'system' to which we refer:

1) The workpiece
2) The cutting tool
3) The chip that is cut from the workpiece by the tool

These give rise to a maximum of 3 real heat sources;

1) The heat source of the shear plane (cutting face)
2) The heat source of the chip-tool interface
3) The heat source of the tool rubbing the workpiece (only for a worn tool)

These are denoted the shear plane, chip-tool interface and flank-work heat sources repectively. Each one gives a contribution to the temperature rise distribution of the system. In our system we can idealise to the extent of eliminating the flank-work heat source by stating that the tool is sharp (radius of tool -> 0), and it therefore does not rub the newly machined surface. If we do not drop this term, as the tool wears (continuous process in time), the flank work heat source increases in length, and a steady-state temperature distribution is never reached in any of the elements of the system. This is very nasty to solve (it has never been done as of end 2001).

The heat-flow equation governing the propagation of heat through our system seems to me to be very similar in appearance to the convective derivative term in the Navier-Stokes equation of fluid dynamics. This describes how heat can diffuse through a stationary body, and can also propagate as the body itself moves (convection).
To progress to a solution of the temperature distribution in our system, we need more information to solve the heat flow equation in each region. This information comes by way of the BOUNDARY CONDITIONS we impose, and these give rise to our IMAGE HEAT SOURCES.