Influence of material melt kinematic viscosity upon treatment quality at fine-jet plasma cutting of bimetallic compositions
The paper reports the peculiarities in the formation of a cut slot of bimetallic “steel 3 + aluminum 5 M” composition and “steel 3 + copper M1” composition at fine-jet plasma cutting. A different character of a cut channel formation of compositions at a package cut on different sides is revealed. When processing “steel + aluminum” composition on the side of steel a cut surface on the aluminum area has course roughness. A burr formation on the lower edge of a cut is also observed. It is explained by considerable difference in melting temperatures and thermal conduction of steel and aluminum. At the changed of a front side of a cut from steel to aluminum occurs sedimentation of aluminum melt on the steel area which is explained by a high kinematic viscosity of aluminum melt. The formation of refractory oxides in aluminum melt is defined that contributes to the increase of its viscosity and difficulty in the complete elimination from a cut channel. At the cutting of bimetallic “steel 3 + copper M1” composition of a copper side a cut surface on both areas is formed without visible traces of sedimentation of steel and copper melt caused by a low kinematic viscosity of copper and steel melts.
