Study of liquid nitrogen cooled micro-milling of PEEK

Abstract

Polyetheretherketone (PEEK) is the specialty plastic that is widely used in space satellites. Due to the poor surface quality of 3D-printed PEEK, the silver lines printed on the surface will diffuse after curing. To address these issues, this paper proposed a liquid nitrogen cooling assisted micro-milling PEEK material, and analyzed the influence of three different temperatures (high temperature 140 ℃, normal temperature 25 ℃, low temperature -196 ℃) on the hardness of PEEK, and optimized the milling parameters (feed per tooth) through single factor experiments to reduce the surface roughness, and finally achieved the purpose of reducing the diffusion degree of silver lines. The result demonstrated liquid nitrogen could reduce the intermolecular force, increase the hardness and reduce surface roughness. When the feed per tooth was 1.5 μm/z, the surface roughness was reduced to minimum (0.2234 μm) at low temperature, and the diffusion degree of silver lines were greatly reduced.