End milling machinability studies for steel, a nickel-base alloy (Inconel 718) and a metal matrix composite

摘要

Nickel based superalloys and MMCs are advanced materials which are used in aerospace, automotive, defence industries etc.. In general, these materials are difficult to machine. This thesis describes a study of machinability assessment of Inconel 718", a nickel base superalloy and 2618m MMC, a MMC based on aluminium alloy (matrix metal) and 12% vf. SiCp (reinforcement), using uncoated carbide inserts. In addition to the machining of these two materials preliminary cutting tests were carried out on steel (190 BHN) using HSS solid end mills. Through out the experiment the cutting tests were conducted under dry conditions. The experiments may be summarised as follows:udud— An investigation of cutting forces, tool life and surface finish in end milling Inconel 718ud— Development of the mathematical models for machining responses by Response Surface Methodology: The mathematical models for machining responses ( cutting forces, tool life and surface finish ) are developed in terms of primary machining variables like cutting speed, feed and axial depth of cut. The mathematical models for machining responses cover the following areas:udud(a) Cutting force models for slot milling steel (190 BHN) and Inconel 718ud(b) Tool life models for slot milling steel (190 BHN)ud(c) Surface roughness models for slot milling steel (190 BHN), Inconel 718 and 2618 MMC.