Session: 02-04-01: Session #1: Advanced Machining and Finishing Processes

Paper Number: 95233

95233 - Modeling and Simulation of Chip-Flow in Grinding of Different Materials – AlMg5 and C45 

Grinding offers specific advantages in comparison with other machining processes. In many cases, grinding proves to be the only economic material removal process. The trend in industrial production toward higher productivity with increased part accuracy, using harder-to-machine materials, naturally leads to the increasing use of grinding to solve many material removal challenges. In many situations grinding is regarded as an art best handled by a skilled machine operator with years of experience. However, current technological advancements and innovation trends require science-based solutions capable to provide accurate models of the chip formation process, enabling optimization and control. The aim of this paper is to develop an adequate chip-formation model resulting in a realistic grinding chip with corresponding influence on the workpiece. The developed fundamental equations in metal plasticity, are relevant for each material and their alloys; so that the total chip-flow with discontinuity and corresponding body forces can be solved. In addition, the resulting self-hardening effect as well as the created temperatures – due to the deformation process – will be discussed and presented. Despite the large number of investigations and simulations, there is still no clarity on these existing subjects. All these phenomena can’t be solved separately because all influencing parameters have an interdependent relationship. The newly developed mathematical equations for strain and stress lead to square grid deformation in the chip formation zone, and this grid deformation will not disappear after completing the grinding process, so that the theoretical developments can be compared with practical results. As long as the created theoretical result will fit the practical result, we can be sure that we are on a relevant, realistic path. This will be presented for two different materials AlMg5 and the carbon steel C45. For the material AlMg5 we get a chip with integration of different plastic layers bonding together as a complete spherical grinding chip. These phenomena lead to a change of the active cutting space of a grinding wheel by covering the pore volume and coating the cutting edges. The result is characterized by higher grinding forces, rough and thermally influenced workpiece surface. Quite contrary is the chip formation of the carbon steel C45. As a result of self-blockade at the interface between material and cutting edge, a segmented chip will follow with dynamic forces and a chattering process influencing the total machine behavior as well as the workpiece roundness and resulting surface. Finally, a high agreement between the developed theoretical and experimental results could be documented.

Presenting Author: Wolfgang Lortz University of Applied Sciences, Schneidershof

Presenting Author Biography: Professor

Authors:

Wolfgang Lortz University of Applied Sciences, Schneidershof
Radu Pavel Techsolve, Inc.