Optimization and experimental modeling of quality characteristics for difficult to laser cut aluminum alloy sheets

Abstract

Development of advanced engineering materials, stringent design requirement, intricate shape and unusual size and shape of the workpiece restrict the use of conventional machining process. Conventional sheet cutting methods have limitations regarding hardness of sheet material, demand of narrow kerf, complex shapes and intricate profiles. Hence, it was realized that new sheet cutting methods be developed with advanced characteristics known as non-conventional or Advanced Sheet Cutting Methods (ASCMs). Nowadays, many advance sheet cutting methods are being used in industry like Abrasive Jet Cutting (AJC), Water Jet Cutting (WJC), Abrasive Water Jet Cutting (AWJC) and Laser Beam Cutting (LBC) are the examples of ASCMs. AWJC and LBC are more popular due to their cutting capabilities. newlineLaser beam cutting is one of the widely applied ASCMs for cutting of complex shapes and intricate profiles in sheets of different advanced engineering materials. Excellent cut quality and narrow cut kerf are the key features of LBC. This feature maximizes the sheet metal usage by reducing the scrap. LBC is superior to any cutting method, conventional or non-conventional, because of material versatility, no wear or change of tool, high material utilization, production flexibility, high accuracy and edge quality. These unique characteristics of LBC are quite suitable for the improvement productivity. newlineLBC is a thermal energy based non-contact type advanced cutting process in which the material is removed by focusing the high energy density beam on the workpiece surface. Depending upon the prevailing condition, the material may be removed by different mechanism such as vaporization, fusion, reactive fusion, ablation and controlled fracture. The melted material is removed by the flow of high pressure coaxial assist gas jet. The assist gas jet accelerates the transformed material and ejects it from machining zone. The capability of the laser cutting mainly depends on the optical and thermal properties rather than mechanical properties.