Electric arc sweep milling of open channels

Abstract

Electric arc sweep milling is an arc machining process derived from blasting erosion arc machining (BEAM). Purpose of this technology is to increase machining performance of open channels which are extensively used in blisks. In this process, a tool electrode slides above the workpiece surface layer by layer and erodes material by thermal effect to form a complete groove. In this paper, capability of this process is studied initially and effects of input energy on material removal rate (MRR), tool wear ratio (TWR), surface roughness as well as cross section morphology are investigated and the MRR can reach up to 8000 mm3/min with TWR of 2.9%. Based on principle of electric arc sweep milling, in order to machine a groove, there are different possibilities for tool pathway. Therefore, influence of two different tool pathways for machining a simple groove is proposed. Comparison of reciprocating and rectangle pathway shows that in the latter, machining performance improves. The reason is wider clearance between tool electrode and groove wall in rectangle tool pathway that enhances fluid flow and debris particle evacuation in the gap. Therefore, to achieve a good machining result, tool pathway should also be considered for a better fluid distribution.