The Impact of High Speed Machining Technology on the Design and Fabrication of Aerospace Components

Abstract

Abstract Recently, several new machining techniques have been developed which have driven dramatic changes in the manufacture of aerospace components with thin ribs and webs. There are many such components in commercial and military aircraft, and until recently these components we fabricated as sheet metal assemblies. Through an improved understanding of the dynamic interaction between the tool and workpiece, it has now become economically competitive to create components with thin ribs and webs as monolithic units machined from a solid block by milling. Ribs are those thin structures created at the periphery of the end mill, as opposed to webs, which are the thin structures created at the face of the end mill. It is easy to see that as the ribs and webs become thinner, the stiffnesses will decrease, and chatter will become more problematic. Chatter during the machining of such parts can result in damage to the part (even cutting through the thin structure) or at least poor surfaces which require hand finishing. This paper outlines the basic technology required to produce these kinds of components efficiently, and cites several examples.