Influence of the cutting parameters and crystallographic orientation on the surface properties of ductile materials in ultraprecision machining

摘要

The physical properties of highly accurate mechanical components or optical properties of lenses are often linked to the superficial layer heterogeneity of the material. Machined surfaces in ultraprecision techniques (turning or grinding) are not always correctly prepared for finishing operations. In order to understand the impact of this preparation on the surface. properties, it's necessary to quantify the process induced damage, according to the cutting parameters. In this work, we considered a polycrystalline pure aluminium; three samples were machined in SPDT (single point diamond turning), at various parameters. Moreover, in order to understand the crystal's orientation effect, we have established a correlation between two different cases: 1. First, two single crystals of pure aluminium have been machined in SPDT, with similar cutting parameters. 2. Then, we have considered these same parameters to machine a polycrystalline pure aluminium and compared its surface analysis to the single crystals one. The extremely smooth machined surfaces, were characterised using X-Ray grazing incidence analysis, a technique which allows much less than one micron-thick layer investigation.