RESEARCH IN MACHINING HIGH STRENGTH MATERIALS AT ELEVATED TEMPERATURES

Abstract

Tests were run with high strength thermal-resistant work materials selected by surveying U.S. aircraft engineering companies to find representative types of materials presenting problems in convential machining. Each material tested had two different heat treatment procedures. Tests were conducted in orthogonal and conventional turning, in milling and in drilling operations using different methods of workpiece heating. Information was obtained on tool life—cutting speed relationships, tool temperatures and forces, chip formation and related quantites for a range of work temperatures. Metallographic studies of hot-machined parts were carried out and the effects of the process on workpiece geometry are discussed. Assessment of workpiece heating methods will be the subject of a further paper.