The influence of the gas flow regime on the Nd:YAG laser cutting of mullite-alumina

摘要

Mullite-alumina is an advanced ceramic with numerous technological applications due to its excellent resistance to heat, wear and corrosion. The inherent properties of the mullite-alumina such as: very high hardness and brittleness make the machining of the mullite-alumina a very hard work; being noisy, powdery and unsafe for the worker. In a previous work we demonstrated that a pulsed Nd:YAG laser connected to an optical fiber is an efficient tool for the cutting of mullite-alumina plates. In this paper we present the results of the work carried out to understand the role played by the assistant gas. A comparison between the use of a conventional coaxial conical nozzle and an off-axis supersonic nozzle is presented. The results obtained show that the use of a supersonic nozzle leads to a more efficient gas flow dragging of the molten material out of the kerf. Thus, a certain increase in the quality of the cut can be obtained by using the supersonic nozzle.