Optimisation of melt removal in laser cutting

There is a quest in industry to cut faster and deeper, to improve efficiency or open up whole new areas of processing capability. It is clear from an examination of the standard laser cutting process that the laser is more than capable of generating sufficient melt volumes to allow faster or deeper cuts. When such cuts are attempted either they fail or the quality is poor.One of the problems appears to lie with the inadequate axial forces that the coaxial gas jet imparts to the melt volumes within the kerf. Increasing the speed or thickness limits requires better control over the gas jets.This paper examines the effects of fundamental gas jet/material interactions, for both conical and supersonic nozzles using computational fluid dynamics. The work includes a detailed examination of the effect of nozzle offset on the flow through narrow kerfs. Optimum theoretical parameters for assist gas jets are then presented.There is a quest in industry to cut faster and deeper, to improve efficiency or open up whole new areas of processing capability. It is clear from an examination of the standard laser cutting process that the laser is more than capable of generating sufficient melt volumes to allow faster or deeper cuts. When such cuts are attempted either they fail or the quality is poor.One of the problems appears to lie with the inadequate axial forces that the coaxial gas jet imparts to the melt volumes within the kerf. Increasing the speed or thickness limits requires better control over the gas jets.This paper examines the effects of fundamental gas jet/material interactions, for both conical and supersonic nozzles using computational fluid dynamics. The work includes a detailed examination of the effect of nozzle offset on the flow through narrow kerfs. Optimum theoretical parameters for assist gas jets are then presented.