Laser cutting of plasma-sprayed refractory products made of aluminum oxide

Abstract

The possibility of laser cutting of plasma-sprayed refractory products made of aluminum oxide was investigated. The industrial laser complex KS-5VDM1-3 Navigator (VNITEP, Russia), equipped with an LS-3 ytterbium fiber laser with a power of 3 kW, was used to work out the cutting conditions. It was found that immediately after the completion of the plasma spraying process, the phase composition of the article material is a set of various modifications of aluminum oxide. Subsequent heating of these items leads to a series of polymorphic transformations accompanied by changes in the volume and density of the item material. The process ends when all polymorphic modifications of aluminum oxide pass into the only stable phase α-Al2O3 (corundum). It was shown that laser cutting of plasmasprayed aluminum oxide products is possible only when the process of transition of all its phase modifications to corundum is completely completed. Otherwise, a sharp change in the volume of the product material, caused by polymorphic transformations occurring under conditions of a high temperature gradient that occurs during laser cutting, leads to the destruction of the product. Plasmasprayed product, the material of which is entirely α-modification of aluminum oxide (corundum), is not afraid of high temperature gradients and is easily laser cut without destruction. Cutting data can vary widely. The cutting technology of plasma-sprayed refractory products made of aluminum oxide has been mastered at the Scientific and Educational Center for the Implementation of Laser Technologies at the Vladimir State University. Ill. 3. Ref. 13. Tab. 2.