Machining Characteristics of High-gradient Inside Surface Using Long Tool Holder

Abstract

In order to meet the requirements of space reachability, the high-gradient inside surfaces such as infrared optical domes need to be machined with a long tool holder. Under the action of lateral cutting force, the long tool holder is easy to chatter, and the machined surface will roughen. The directionality of cutting force and its influence on chatter marks are studied in the machining process of high-gradient inside surface, and the dynamic model on tool holder is built in this paper. The natural frequency increases to 2820Hz for long tool holder by optimizing its structure and the clamping method, and the dynamic characteristics is greatly improved. The surface roughness is better than Ra 3.3nm for thermocompressed polycrystalline MgF2 parts which are machined in different directions, there aren’t chatter marks on the surface, and the machining requirements are satisfied for infrared optical parts.